diff --git a/CHANGELOG b/CHANGELOG
index 3594e8c1a..07255d78c 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -7,9 +7,13 @@ http://openslides.org
 Version 2.0.0 (unreleased)
 ==========================
 
-- Changed supported Python version to >= 3.3
-- Used Django 1.7 as lowest requirement
-- Refactoring of the participant app. Now called 'users'
+Other:
+- Changed supported Python version to >= 3.3.
+- Used Django 1.7 as lowest requirement.
+- Refactoring of the participant app. Now called 'users'.
+- Added Django's application configuration. Refactored loading of signals,
+  template signals and slides.
+
 
 
 Version 1.6.1 (2014-12-08)
diff --git a/openslides/account/__init__.py b/openslides/account/__init__.py
index a1c0c869e..217ee87bc 100644
--- a/openslides/account/__init__.py
+++ b/openslides/account/__init__.py
@@ -1 +1 @@
-from . import widgets  # noqa
+default_app_config = 'openslides.account.apps.AccountAppConfig'
diff --git a/openslides/account/apps.py b/openslides/account/apps.py
new file mode 100644
index 000000000..bc1350505
--- /dev/null
+++ b/openslides/account/apps.py
@@ -0,0 +1,10 @@
+from django.apps import AppConfig
+
+
+class AccountAppConfig(AppConfig):
+    name = 'openslides.account'
+    verbose_name = 'OpenSlides Account'
+
+    def ready(self):
+        # Load widget.
+        from . import widgets  # noqa
diff --git a/openslides/agenda/__init__.py b/openslides/agenda/__init__.py
index 9e426cdbe..44b39b695 100644
--- a/openslides/agenda/__init__.py
+++ b/openslides/agenda/__init__.py
@@ -1 +1 @@
-from . import main_menu, personal_info, signals, slides, widgets  # noqa
+default_app_config = 'openslides.agenda.apps.AgendaAppConfig'
diff --git a/openslides/agenda/apps.py b/openslides/agenda/apps.py
new file mode 100644
index 000000000..5a1d22f3f
--- /dev/null
+++ b/openslides/agenda/apps.py
@@ -0,0 +1,28 @@
+from django.apps import AppConfig
+
+
+class AgendaAppConfig(AppConfig):
+    name = 'openslides.agenda'
+    verbose_name = 'OpenSlides Agenda'
+
+    def ready(self):
+        # Load main menu entry, personal info and widgets.
+        # Do this by just importing all from these files.
+        from . import main_menu, personal_info, widgets  # noqa
+
+        # Import all required stuff.
+        from django.db.models.signals import pre_delete
+        from openslides.config.signals import config_signal
+        from openslides.projector.api import register_slide
+        from openslides.projector.signals import projector_overlays
+        from .signals import agenda_list_of_speakers, setup_agenda_config, listen_to_related_object_delete_signal
+        from .slides import agenda_slide
+
+        # Connect signals.
+        config_signal.connect(setup_agenda_config, dispatch_uid='setup_agenda_config')
+        projector_overlays.connect(agenda_list_of_speakers, dispatch_uid='agenda_list_of_speakers')
+        pre_delete.connect(listen_to_related_object_delete_signal, dispatch_uid='agenda_listen_to_related_object_delete_signal')
+
+        # Register slides.
+        Item = self.get_model('Item')
+        register_slide('agenda', agenda_slide, Item)
diff --git a/openslides/agenda/forms.py b/openslides/agenda/forms.py
index d5654a0c2..62c5420e1 100644
--- a/openslides/agenda/forms.py
+++ b/openslides/agenda/forms.py
@@ -1,6 +1,6 @@
 import re
-from ckeditor.widgets import CKEditorWidget
 
+from ckeditor.widgets import CKEditorWidget
 from django import forms
 from django.utils.translation import ugettext_lazy
 from mptt.forms import TreeNodeChoiceField
diff --git a/openslides/agenda/signals.py b/openslides/agenda/signals.py
index d1f65c4cf..f87fae70e 100644
--- a/openslides/agenda/signals.py
+++ b/openslides/agenda/signals.py
@@ -3,17 +3,13 @@ from datetime import datetime
 from django import forms
 from django.contrib.contenttypes.models import ContentType
 from django.core.exceptions import ValidationError
-from django.db.models.signals import pre_delete
-from django.dispatch import receiver
 from django.template.loader import render_to_string
 from django.utils.translation import ugettext as _
 from django.utils.translation import ugettext_lazy, ugettext_noop
 
 from openslides.config.api import config, ConfigCollection, ConfigVariable
-from openslides.config.signals import config_signal
 from openslides.projector.api import get_active_slide, get_active_object
 from openslides.projector.projector import Overlay
-from openslides.projector.signals import projector_overlays
 
 from .models import Item
 
@@ -27,10 +23,10 @@ def validate_start_time(value):
 
 # TODO: Reinsert the datepicker scripts in the template
 
-@receiver(config_signal, dispatch_uid='setup_agenda_config')
 def setup_agenda_config(sender, **kwargs):
     """
-    Agenda config variables.
+    Receiver function to setup all agenda config variables. It is connected to
+    the signal openslides.config.signals.config_signal during app loading.
     """
     # TODO: Insert validator for the format or use other field carefully.
     agenda_start_event_date_time = ConfigVariable(
@@ -94,10 +90,11 @@ def setup_agenda_config(sender, **kwargs):
                                            'extra_javascript': extra_javascript})
 
 
-@receiver(projector_overlays, dispatch_uid="agenda_list_of_speakers")
 def agenda_list_of_speakers(sender, **kwargs):
     """
-    Receiver for the list of speaker overlay.
+    Receiver function to setup the list of speaker overlay. It is connected
+    to the signal openslides.projector.signals.projector_overlays during
+    app loading.
     """
     name = 'agenda_speaker'
 
@@ -141,10 +138,11 @@ def agenda_list_of_speakers(sender, **kwargs):
     return Overlay(name, get_widget_html, get_projector_html)
 
 
-@receiver(pre_delete)
 def listen_to_related_object_delete_signal(sender, instance, **kwargs):
     """
-    Receiver to listen whether a related item has been deleted.
+    Receiver function to changed agenda items of a related items that is to
+    be deleted. It is connected to the signal
+    django.db.models.signals.pre_delete during app loading.
     """
     if hasattr(instance, 'get_agenda_title'):
         for item in Item.objects.filter(content_type=ContentType.objects.get_for_model(sender), object_id=instance.pk):
diff --git a/openslides/agenda/slides.py b/openslides/agenda/slides.py
index 7c702a566..171a84086 100644
--- a/openslides/agenda/slides.py
+++ b/openslides/agenda/slides.py
@@ -1,7 +1,7 @@
 from django.template.loader import render_to_string
 
 from openslides.config.api import config
-from openslides.projector.api import get_projector_content, register_slide
+from openslides.projector.api import get_projector_content
 
 from .models import Item
 
@@ -19,6 +19,8 @@ def agenda_slide(**kwargs):
     If 'type' is 'summary', show a summary of all children of the item.
 
     If 'type' is 'list_of_speakers', show the list of speakers for the item.
+
+    The function is registered during app loading.
     """
     item_pk = kwargs.get('pk', None)
     slide_type = kwargs.get('type', None)
@@ -56,6 +58,3 @@ def agenda_slide(**kwargs):
         context = {'item': item}
         slide = render_to_string('agenda/item_slide.html', context)
     return slide
-
-
-register_slide('agenda', agenda_slide, Item)
diff --git a/openslides/assignment/__init__.py b/openslides/assignment/__init__.py
index eff95fa33..5eff81229 100644
--- a/openslides/assignment/__init__.py
+++ b/openslides/assignment/__init__.py
@@ -1 +1 @@
-# TODO: apploader
+default_app_config = 'openslides.assignment.apps.AssignmentAppConfig'
diff --git a/openslides/assignment/apps.py b/openslides/assignment/apps.py
new file mode 100644
index 000000000..1331ed1e8
--- /dev/null
+++ b/openslides/assignment/apps.py
@@ -0,0 +1,30 @@
+from django.apps import AppConfig
+
+
+class AssignmentAppConfig(AppConfig):
+    name = 'openslides.assignment'
+    verbose_name = 'OpenSlides Assignment'
+
+    def ready(self):
+        # Load main menu entry, personal info and widgets.
+        # Do this by just importing all from these files.
+        from . import main_menu, personal_info, widgets  # noqa
+
+        # Import all required stuff.
+        from openslides.config.signals import config_signal
+        from openslides.projector.api import register_slide_model
+        from openslides.utils.signals import template_manipulation
+        from .signals import setup_assignment_config
+        from .template import add_assignment_stylesheets
+
+        # Connect signals.
+        config_signal.connect(setup_assignment_config, dispatch_uid='setup_assignment_config')
+
+        # Connect template signal.
+        template_manipulation.connect(add_assignment_stylesheets, dispatch_uid='add_assignment_stylesheets')
+
+        # Register slides.
+        Assignment = self.get_model('Assignment')
+        AssignmentPoll = self.get_model('AssignmentPoll')
+        register_slide_model(Assignment, 'assignment/slide.html')
+        register_slide_model(AssignmentPoll, 'assignment/assignmentpoll_slide.html')
diff --git a/openslides/assignment/models.py b/openslides/assignment/models.py
index 460c86780..dd9cd17ef 100644
--- a/openslides/assignment/models.py
+++ b/openslides/assignment/models.py
@@ -342,7 +342,3 @@ class AssignmentPoll(SlideMixin, RelatedModelMixin, CollectDefaultVotesMixin,
 
     def get_slide_context(self, **context):
         return super(AssignmentPoll, self).get_slide_context(poll=self)
-
-
-# TODO: use the app framework
-from . import main_menu, personal_info, signals, slides, template, widgets  # noqa
diff --git a/openslides/assignment/signals.py b/openslides/assignment/signals.py
index ca71339fa..56774c30e 100644
--- a/openslides/assignment/signals.py
+++ b/openslides/assignment/signals.py
@@ -1,17 +1,16 @@
 from django import forms
-from django.dispatch import receiver
 from django.utils.translation import ugettext as _
 from django.utils.translation import ugettext_lazy, ugettext_noop
 
 from openslides.config.api import ConfigGroup, ConfigGroupedCollection, ConfigVariable
-from openslides.config.signals import config_signal
 from openslides.poll.models import PERCENT_BASE_CHOICES
 
 
-@receiver(config_signal, dispatch_uid='setup_assignment_config')
 def setup_assignment_config(sender, **kwargs):
     """
-    Assignment config variables.
+    Receiver function to setup all assignment config variables. It is
+    connected to the signal openslides.config.signals.config_signal during
+    app loading.
     """
     # Ballot and ballot papers
     assignment_poll_vote_values = ConfigVariable(
diff --git a/openslides/assignment/slides.py b/openslides/assignment/slides.py
deleted file mode 100644
index d3627c109..000000000
--- a/openslides/assignment/slides.py
+++ /dev/null
@@ -1,6 +0,0 @@
-from openslides.projector.api import register_slide_model
-
-from .models import Assignment, AssignmentPoll
-
-register_slide_model(Assignment, 'assignment/slide.html')
-register_slide_model(AssignmentPoll, 'assignment/assignmentpoll_slide.html')
diff --git a/openslides/assignment/template.py b/openslides/assignment/template.py
index 0df923112..5cb21bb03 100644
--- a/openslides/assignment/template.py
+++ b/openslides/assignment/template.py
@@ -1,11 +1,7 @@
-from django.dispatch import receiver
-
-from openslides.utils.signals import template_manipulation
-
-
-@receiver(template_manipulation, dispatch_uid="add_assignment_stylesheets")
 def add_assignment_stylesheets(sender, request, context, **kwargs):
     """
-    Adds the assignment.css to the context.
+    Receiver function to add the assignment.css to the context. It is
+    connected to the signal openslides.utils.signals.template_manipulation
+    during app loading.
     """
     context['extra_stylefiles'].append('css/assignment.css')
diff --git a/openslides/config/__init__.py b/openslides/config/__init__.py
index 8d15e06d4..2c5bdbda5 100644
--- a/openslides/config/__init__.py
+++ b/openslides/config/__init__.py
@@ -1 +1 @@
-from . import main_menu  # noqa
+default_app_config = 'openslides.config.apps.ConfigAppConfig'
diff --git a/openslides/config/apps.py b/openslides/config/apps.py
new file mode 100644
index 000000000..5fe9d414a
--- /dev/null
+++ b/openslides/config/apps.py
@@ -0,0 +1,11 @@
+from django.apps import AppConfig
+
+
+class ConfigAppConfig(AppConfig):
+    name = 'openslides.config'
+    verbose_name = 'OpenSlides Config'
+
+    def ready(self):
+        # Load main menu entry.
+        # Do this by just importing all from this file.
+        from . import main_menu  # noqa
diff --git a/openslides/core/__init__.py b/openslides/core/__init__.py
index b0ad1bf8f..8c0054d41 100644
--- a/openslides/core/__init__.py
+++ b/openslides/core/__init__.py
@@ -1 +1 @@
-# TODO: apploading
+default_app_config = 'openslides.core.apps.CoreAppConfig'
diff --git a/openslides/core/apps.py b/openslides/core/apps.py
new file mode 100644
index 000000000..fb0fa62e0
--- /dev/null
+++ b/openslides/core/apps.py
@@ -0,0 +1,23 @@
+from django.apps import AppConfig
+
+
+class CoreAppConfig(AppConfig):
+    name = 'openslides.core'
+    verbose_name = 'OpenSlides Core'
+
+    def ready(self):
+        # Load main menu entry and widgets.
+        # Do this by just importing all from these files.
+        from . import main_menu, widgets  # noqa
+
+        # Import all required stuff.
+        from openslides.config.signals import config_signal
+        from openslides.projector.api import register_slide_model
+        from .signals import setup_general_config
+
+        # Connect signals.
+        config_signal.connect(setup_general_config, dispatch_uid='setup_general_config')
+
+        # Register slides.
+        CustomSlide = self.get_model('CustomSlide')
+        register_slide_model(CustomSlide, 'core/customslide_slide.html')
diff --git a/openslides/core/models.py b/openslides/core/models.py
index 86b5a4783..f9a8aef42 100644
--- a/openslides/core/models.py
+++ b/openslides/core/models.py
@@ -44,7 +44,3 @@ class CustomSlide(SlideMixin, AbsoluteUrlMixin, models.Model):
         else:
             url = super(CustomSlide, self).get_absolute_url(link)
         return url
-
-
-# TODO: apploader
-from . import main_menu, signals, slides, widgets  # noqa
diff --git a/openslides/core/signals.py b/openslides/core/signals.py
index 4cf36ae16..aae6de38d 100644
--- a/openslides/core/signals.py
+++ b/openslides/core/signals.py
@@ -1,20 +1,20 @@
 from django import forms
-from django.dispatch import receiver, Signal
+from django.dispatch import Signal
 from django.utils.translation import ugettext as _
 from django.utils.translation import ugettext_lazy, ugettext_noop
 
 from openslides.config.api import ConfigGroup, ConfigGroupedCollection, ConfigVariable
-from openslides.config.signals import config_signal
 from openslides.projector.api import update_projector
 
 post_database_setup = Signal()
 
 
-@receiver(config_signal, dispatch_uid='setup_general_config')
 def setup_general_config(sender, **kwargs):
     """
-    General config variables for OpenSlides. They are grouped in 'Event',
-    'Welcome Widget' and 'System'.
+    Receiver function to setup general config variables for OpenSlides.
+    They are grouped in 'Event', 'Welcome Widget' and 'System'. The
+    function is connected to the signal
+    openslides.config.signals.config_signal during app loading.
     """
     event_name = ConfigVariable(
         name='event_name',
diff --git a/openslides/core/slides.py b/openslides/core/slides.py
deleted file mode 100644
index 1a6e4e948..000000000
--- a/openslides/core/slides.py
+++ /dev/null
@@ -1,5 +0,0 @@
-from openslides.projector.api import register_slide_model
-
-from .models import CustomSlide
-
-register_slide_model(CustomSlide, 'core/customslide_slide.html')
diff --git a/openslides/core/widgets.py b/openslides/core/widgets.py
index 5b809f9cd..f5a350cdb 100644
--- a/openslides/core/widgets.py
+++ b/openslides/core/widgets.py
@@ -36,8 +36,11 @@ class CustonSlideWidget(Widget):
     icon_css_class = 'icon-star'
 
     def get_context_data(self, **context):
-        return super(CustonSlideWidget, self).get_context_data(
-            slides=CustomSlide.objects.all().order_by('weight'),
-            welcomepage_is_active=(
-                get_active_slide().get('callback', 'default') == 'default'),
-            **context)
+        """
+        Adds custom slides and a flag whether the welcome page is active to
+        the context.
+        """
+        context['slides'] = CustomSlide.objects.all().order_by('weight')
+        context['welcomepage_is_active'] = (
+            get_active_slide().get('callback', 'default') == 'default')
+        return super(CustonSlideWidget, self).get_context_data(**context)
diff --git a/openslides/mediafile/__init__.py b/openslides/mediafile/__init__.py
index a308af592..352bdc7eb 100644
--- a/openslides/mediafile/__init__.py
+++ b/openslides/mediafile/__init__.py
@@ -1 +1 @@
-from . import main_menu, slides, template, widgets  # noqa
+default_app_config = 'openslides.mediafile.apps.MediafileAppConfig'
diff --git a/openslides/mediafile/apps.py b/openslides/mediafile/apps.py
new file mode 100644
index 000000000..9dc0b4b92
--- /dev/null
+++ b/openslides/mediafile/apps.py
@@ -0,0 +1,24 @@
+from django.apps import AppConfig
+
+
+class MediafileAppConfig(AppConfig):
+    name = 'openslides.mediafile'
+    verbose_name = 'OpenSlides Mediafile'
+
+    def ready(self):
+        # Load main menu entry and widgets.
+        # Do this by just importing all from these files.
+        from . import main_menu, widgets  # noqa
+
+        # Import all required stuff.
+        from openslides.projector.api import register_slide
+        from openslides.utils.signals import template_manipulation
+        from .slides import mediafile_presentation_as_slide
+        from .template import add_mediafile_stylesheets
+
+        # Connect template signal.
+        template_manipulation.connect(add_mediafile_stylesheets, dispatch_uid='add_mediafile_stylesheets')
+
+        # Register slides.
+        Mediafile = self.get_model('Mediafile')
+        register_slide('mediafile', mediafile_presentation_as_slide, Mediafile)
diff --git a/openslides/mediafile/slides.py b/openslides/mediafile/slides.py
index da1b8feab..84d69621e 100644
--- a/openslides/mediafile/slides.py
+++ b/openslides/mediafile/slides.py
@@ -1,9 +1,7 @@
-#!/usr/bin/env python
-
 from django.template.loader import render_to_string
 
 from openslides.config.api import config
-from openslides.projector.api import register_slide, SlideError
+from openslides.projector.api import SlideError
 
 from .models import Mediafile
 
@@ -13,6 +11,8 @@ def mediafile_presentation_as_slide(**kwargs):
     Return the html code for a presentation of a Mediafile.
 
     At the moment, only the presentation of pdfs is supported.
+
+    The function is registered during app loading.
     """
     file_pk = kwargs.get('pk', None)
     page_num = kwargs.get('page_num', 1)
@@ -27,6 +27,3 @@ def mediafile_presentation_as_slide(**kwargs):
     context = {'pdf': pdf, 'page_num': page_num,
                'fullscreen': config['pdf_fullscreen']}
     return render_to_string('mediafile/presentation_slide.html', context)
-
-
-register_slide('mediafile', mediafile_presentation_as_slide, Mediafile)
diff --git a/openslides/mediafile/template.py b/openslides/mediafile/template.py
index 6d4c61bf2..90dc78de1 100644
--- a/openslides/mediafile/template.py
+++ b/openslides/mediafile/template.py
@@ -1,11 +1,7 @@
-from django.dispatch import receiver
-
-from openslides.utils.signals import template_manipulation
-
-
-@receiver(template_manipulation, dispatch_uid="add_mediafile_stylesheets")
 def add_mediafile_stylesheets(sender, request, context, **kwargs):
     """
-    Adds the mediafile.css to the context.
+    Receiver function to add the mediafile.css to the context. It is
+    connected to the signal openslides.utils.signals.template_manipulation
+    during app loading.
     """
     context['extra_stylefiles'].append('css/mediafile.css')
diff --git a/openslides/motion/__init__.py b/openslides/motion/__init__.py
index 498f2dd6f..544a0c792 100644
--- a/openslides/motion/__init__.py
+++ b/openslides/motion/__init__.py
@@ -1 +1 @@
-# TODO: Apploading
+default_app_config = 'openslides.motion.apps.MotionAppConfig'
diff --git a/openslides/motion/apps.py b/openslides/motion/apps.py
new file mode 100644
index 000000000..e5ecdfe71
--- /dev/null
+++ b/openslides/motion/apps.py
@@ -0,0 +1,27 @@
+from django.apps import AppConfig
+
+
+class MotionAppConfig(AppConfig):
+    name = 'openslides.motion'
+    verbose_name = 'OpenSlides Motion'
+
+    def ready(self):
+        # Load main menu entry, personal info and widgets.
+        # Do this by just importing all from these files.
+        from . import main_menu, personal_info, widgets  # noqa
+
+        # Import all required stuff.
+        from openslides.config.signals import config_signal
+        from openslides.core.signals import post_database_setup
+        from openslides.projector.api import register_slide_model
+        from .signals import create_builtin_workflows, setup_motion_config
+
+        # Connect signals.
+        config_signal.connect(setup_motion_config, dispatch_uid='setup_motion_config')
+        post_database_setup.connect(create_builtin_workflows, dispatch_uid='motion_create_builtin_workflows')
+
+        # Register slides.
+        Motion = self.get_model('Motion')
+        MotionPoll = self.get_model('MotionPoll')
+        register_slide_model(Motion, 'motion/slide.html')
+        register_slide_model(MotionPoll, 'motion/motionpoll_slide.html')
diff --git a/openslides/motion/models.py b/openslides/motion/models.py
index bc7ad0e2d..669a3442c 100644
--- a/openslides/motion/models.py
+++ b/openslides/motion/models.py
@@ -852,7 +852,3 @@ class Workflow(models.Model):
             raise WorkflowError(
                 '%s can not be first state of %s because it '
                 'does not belong to it.' % (self.first_state, self))
-
-
-# TODO: Apploading
-from . import main_menu, personal_info, signals, slides, widgets  # noqa
diff --git a/openslides/motion/signals.py b/openslides/motion/signals.py
index 6b030471d..69d1ebf1b 100644
--- a/openslides/motion/signals.py
+++ b/openslides/motion/signals.py
@@ -1,20 +1,17 @@
 from django import forms
-from django.dispatch import receiver
 from django.utils.translation import ugettext as _
 from django.utils.translation import ugettext_lazy, ugettext_noop
 
 from openslides.config.api import ConfigGroup, ConfigGroupedCollection, ConfigVariable
-from openslides.config.signals import config_signal
-from openslides.core.signals import post_database_setup
 from openslides.poll.models import PERCENT_BASE_CHOICES
 
 from .models import State, Workflow
 
 
-@receiver(config_signal, dispatch_uid='setup_motion_config')
 def setup_motion_config(sender, **kwargs):
     """
-    Motion config variables.
+    Receiver function to setup all motion config variables. It is connected to
+    the signal openslides.config.signals.config_signal during app loading.
     """
     # General
     motion_workflow = ConfigVariable(
@@ -149,10 +146,11 @@ def setup_motion_config(sender, **kwargs):
         groups=(group_general, group_supporters, group_ballot_papers, group_pdf))
 
 
-@receiver(post_database_setup, dispatch_uid='motion_create_builtin_workflows')
 def create_builtin_workflows(sender, **kwargs):
     """
-    Creates a simple and a complex workflow.
+    Receiver function to create a simple and a complex workflow. It is
+    connected to the signal openslides.core.signals.post_database_setup
+    during app loading.
     """
     workflow_1, created = Workflow.objects.get_or_create(name=ugettext_noop('Simple Workflow'))
     if created:
diff --git a/openslides/motion/slides.py b/openslides/motion/slides.py
deleted file mode 100644
index ae4472e64..000000000
--- a/openslides/motion/slides.py
+++ /dev/null
@@ -1,6 +0,0 @@
-from openslides.projector.api import register_slide_model
-
-from .models import Motion, MotionPoll
-
-register_slide_model(Motion, 'motion/slide.html')
-register_slide_model(MotionPoll, 'motion/motionpoll_slide.html')
diff --git a/openslides/poll/__init__.py b/openslides/poll/__init__.py
index e69de29bb..3fc3b0abb 100644
--- a/openslides/poll/__init__.py
+++ b/openslides/poll/__init__.py
@@ -0,0 +1,2 @@
+# This app uses Django's base AppConfig class so the variable
+# default_app_config is not defined.
diff --git a/openslides/projector/__init__.py b/openslides/projector/__init__.py
index 05f9e673d..f610c41af 100644
--- a/openslides/projector/__init__.py
+++ b/openslides/projector/__init__.py
@@ -1 +1 @@
-from . import signals, widgets  # noqa
+default_app_config = 'openslides.projector.apps.ProjectorAppConfig'
diff --git a/openslides/projector/apps.py b/openslides/projector/apps.py
new file mode 100644
index 000000000..5c02769c1
--- /dev/null
+++ b/openslides/projector/apps.py
@@ -0,0 +1,23 @@
+from django.apps import AppConfig
+
+
+class ProjectorAppConfig(AppConfig):
+    name = 'openslides.projector'
+    verbose_name = 'OpenSlides Projector'
+
+    def ready(self):
+        # Load widgets.
+        # Do this by just importing all from this file.
+        from . import widgets  # noqa
+
+        # Import all required stuff.
+        from openslides.config.signals import config_signal
+        from .signals import (
+            countdown, projector_clock, projector_overlays,
+            projector_overlay_message, setup_projector_config)
+
+        # Connect signals.
+        config_signal.connect(setup_projector_config, dispatch_uid='setup_projector_config')
+        projector_overlays.connect(countdown, dispatch_uid="projector_countdown")
+        projector_overlays.connect(projector_overlay_message, dispatch_uid="projector_overlay_message")
+        projector_overlays.connect(projector_clock, dispatch_uid="projector_clock")
diff --git a/openslides/projector/projector.py b/openslides/projector/projector.py
index 418450d42..0d14b29de 100644
--- a/openslides/projector/projector.py
+++ b/openslides/projector/projector.py
@@ -1,6 +1,5 @@
 import warnings
 
-
 from openslides.config.api import config
 
 from .exceptions import ProjectorExceptionWarning
diff --git a/openslides/projector/signals.py b/openslides/projector/signals.py
index 973c3737a..b75710e29 100644
--- a/openslides/projector/signals.py
+++ b/openslides/projector/signals.py
@@ -2,23 +2,22 @@ from time import time
 
 from django.contrib.staticfiles.templatetags.staticfiles import static
 from django.core.context_processors import csrf
-from django.dispatch import receiver, Signal
+from django.dispatch import Signal
 from django.template.loader import render_to_string
 from django.utils.datastructures import SortedDict
 
 from openslides.config.api import config, ConfigCollection, ConfigVariable
-from openslides.config.signals import config_signal
 
 from .projector import Overlay
 
 projector_overlays = Signal(providing_args=['request'])
 
 
-@receiver(config_signal, dispatch_uid='setup_projector_config')
 def setup_projector_config(sender, **kwargs):
     """
-    Projector config variables for OpenSlides. They are not shown on a
-    config view.
+    Receiver function to setup all projector config variables. They are not
+    shown on a config view. The function is connected to the signal
+    openslides.config.signals.config_signal during app loading.
     """
     # The active slide. The config-value is a dictonary with at least the entry
     # 'callback'.
@@ -75,10 +74,10 @@ def setup_projector_config(sender, **kwargs):
             projector_pdf_fullscreen))
 
 
-@receiver(projector_overlays, dispatch_uid="projector_countdown")
 def countdown(sender, **kwargs):
     """
-    Receiver for the countdown.
+    Receiver function for the projector countdown. The function is
+    connected to the signal projector_overlays during app loading.
     """
     name = 'projector_countdown'
     request = kwargs.get('request', None)
@@ -116,11 +115,11 @@ def countdown(sender, **kwargs):
     return Overlay(name, get_widget_html, get_projector_html, get_projector_js)
 
 
-@receiver(projector_overlays, dispatch_uid="projector_overlay_message")
 def projector_overlay_message(sender, **kwargs):
     """
-    Receiver to show the overlay_message on the projector or the form in the
-    overlay-widget on the dashboard.
+    Receiver function to show the overlay_message on the projector or the
+    form in the overlay-widget on the dashboard. The function is connected
+    to the signal projector_overlays during app loading.
     """
     name = 'projector_message'
     request = kwargs.get('request', None)
@@ -143,10 +142,10 @@ def projector_overlay_message(sender, **kwargs):
     return Overlay(name, get_widget_html, get_projector_html)
 
 
-@receiver(projector_overlays, dispatch_uid="projector_clock")
 def projector_clock(sender, **kwargs):
     """
-    Receiver to show the clock on the projector.
+    Receiver function to show the clock on the projector. The function is
+    connected to the signal projector_overlays during app loading.
     """
     name = 'projector_clock'
 
diff --git a/openslides/users/__init__.py b/openslides/users/__init__.py
index a5dd689db..a12602089 100644
--- a/openslides/users/__init__.py
+++ b/openslides/users/__init__.py
@@ -1 +1 @@
-from . import main_menu, signals, slides, widgets  # noqa
+default_app_config = 'openslides.users.apps.UsersAppConfig'
diff --git a/openslides/users/apps.py b/openslides/users/apps.py
new file mode 100644
index 000000000..33b66a983
--- /dev/null
+++ b/openslides/users/apps.py
@@ -0,0 +1,29 @@
+from django.apps import AppConfig
+
+
+class UsersAppConfig(AppConfig):
+    name = 'openslides.users'
+    verbose_name = 'OpenSlides Users'
+
+    def ready(self):
+        # Load main menu entry and widgets.
+        # Do this by just importing all from these files.
+        from . import main_menu, widgets  # noqa
+
+        # Import all required stuff.
+        from django.db.models.signals import post_save
+        from openslides.config.signals import config_signal
+        from openslides.core.signals import post_database_setup
+        from openslides.projector.api import register_slide_model
+        from .signals import create_builtin_groups_and_admin, setup_users_config, user_post_save
+
+        # Load User model.
+        User = self.get_model('User')
+
+        # Connect signals.
+        config_signal.connect(setup_users_config, dispatch_uid='setup_users_config')
+        post_database_setup.connect(create_builtin_groups_and_admin, dispatch_uid='users_create_builtin_groups_and_admin')
+        post_save.connect(user_post_save, sender=User, dispatch_uid='users_user_post_save')
+
+        # Register slides.
+        register_slide_model(User, 'participant/user_slide.html')
diff --git a/openslides/users/signals.py b/openslides/users/signals.py
index 5c44da2fc..af0be40f9 100644
--- a/openslides/users/signals.py
+++ b/openslides/users/signals.py
@@ -1,23 +1,19 @@
 from django import forms
 from django.contrib.auth.models import Permission
 from django.contrib.contenttypes.models import ContentType
-from django.dispatch import receiver
 from django.utils.translation import ugettext as _
 from django.utils.translation import ugettext_lazy, ugettext_noop
-from django.db.models import signals
 
 from openslides.config.api import ConfigGroup, ConfigGroupedCollection, ConfigVariable
-from openslides.config.signals import config_signal
-from openslides.core.signals import post_database_setup
 
 from .api import create_or_reset_admin_user
-from .models import Group, User
+from .models import Group
 
 
-@receiver(config_signal, dispatch_uid='setup_users_config')
 def setup_users_config(sender, **kwargs):
     """
-    Participant config variables.
+    Receiver function to setup all users config variables. It is connected
+    to the signal openslides.config.signals.config_signal during app loading.
     """
     # General
     users_sort_users_by_first_name = ConfigVariable(
@@ -108,14 +104,16 @@ def setup_users_config(sender, **kwargs):
         groups=(group_general, group_pdf))
 
 
-@receiver(post_database_setup, dispatch_uid='users_create_builtin_groups_and_admin')
 def create_builtin_groups_and_admin(sender, **kwargs):
     """
-    Creates the buildin groups and the admin user.
+    Receiver function to builtin groups and the admin user.
 
     Creates the builtin groups: Anonymous, Registered, Delegates and Staff.
 
     Creates the builtin user: admin.
+
+    It is connected to the signal
+    openslides.core.signals.post_database_setup during app loading.
     """
     # Check whether the group pks 1 to 4 are free
     if Group.objects.filter(pk__in=range(1, 5)).exists():
@@ -184,8 +182,12 @@ def create_builtin_groups_and_admin(sender, **kwargs):
     create_or_reset_admin_user()
 
 
-@receiver(signals.post_save, sender=User)
 def user_post_save(sender, instance, *args, **kwargs):
+    """
+    Receiver function to add a new user to the registered group. It is
+    connected to the signal django.db.models.signals.post_save during app
+    loading.
+    """
     if not kwargs['created']:
         return
 
diff --git a/openslides/users/slides.py b/openslides/users/slides.py
deleted file mode 100644
index 1bdcfa892..000000000
--- a/openslides/users/slides.py
+++ /dev/null
@@ -1,5 +0,0 @@
-from openslides.projector.api import register_slide_model
-
-from .models import User
-
-register_slide_model(User, 'participant/user_slide.html')