diff --git a/polls/models.py b/polls/models.py
index ee242eb..6cac1ef 100644
--- a/polls/models.py
+++ b/polls/models.py
@@ -45,7 +45,8 @@ class Notice(models.Model):
     type = models.IntegerField(
         'category', choices=NOTICE_TYPE_CHOICES, default=0)
     content = models.CharField('内容', max_length=256, null=False)
-    group_id = models.CharField('group_id', max_length=256, null=True, blank=True)
+    group_id = models.CharField(
+        'group_id', max_length=256, null=True, blank=True)
     app = models.CharField('app', max_length=256, null=True, blank=True)
     model = models.CharField('model', max_length=256, null=True, blank=True)
     field = models.CharField('field', max_length=256, null=True, blank=True)
@@ -112,7 +113,6 @@ class Task(models.Model):
             Message.objects.create(
                 type=1, send_from_id=user_id, send_to_id=group.id, task=self, page_title=title, page_description=description, page_image=image, url=url)
 
-
     class Meta:
         ordering = ["-added"]
 
@@ -206,3 +206,10 @@ class GroupRecord(models.Model):
     leave_at = models.DateTimeField(auto_now=True)
     added = models.DateTimeField(auto_now_add=True)
     updated = models.DateTimeField(auto_now=True)
+
+
+class AppVersion(models.Model):
+    id = models.UUIDField('id', primary_key=True, default=uuid.uuid4)
+    version = models.IntegerField('version', default=1)
+    added = models.DateTimeField(auto_now_add=True)
+    updated = models.DateTimeField(auto_now=True)
\ No newline at end of file
diff --git a/polls/views/__init__.py b/polls/views/__init__.py
index fe7304a..6879918 100644
--- a/polls/views/__init__.py
+++ b/polls/views/__init__.py
@@ -8,4 +8,4 @@ from .group import groups, room, is_level1_or_leve2, group_member, group_manager
 from .compartment import compartments
 from .organizations import organizations, organization_level
 from .message import last_messages, send_text_message, is_read_message, read_message
-from .download import download, app_intro
+from .app import download, app_intro
diff --git a/polls/views/app.py b/polls/views/app.py
new file mode 100644
index 0000000..ee58de1
--- /dev/null
+++ b/polls/views/app.py
@@ -0,0 +1,29 @@
+import os
+from django.conf import settings
+from django.http import Http404, HttpResponse, JsonResponse
+from django.shortcuts import render
+from polls.models import AppVersion
+
+
+def app_intro(request):
+    return render(request, 'polls/app.html')
+
+
+def download(request):
+    app = AppVersion.objects.last('version')
+    filename = 'app-%s.apk' % (app.version,)
+    file_path = os.path.join(settings.MEDIA_ROOT, filename)
+    if os.path.exists(file_path):
+        with open(file_path, 'rb') as fh:
+            response = HttpResponse(
+                fh.read(), content_type="application/vnd.android.package-archive")
+            response['Content-Disposition'] = 'inline; filename=' + \
+                os.path.basename(file_path)
+            return response
+    raise Http404
+
+
+def has_update(request):
+    version = request.GET.get('version', '1')
+    last = AppVersion.objects.last('version')
+    return JsonResponse({'status': 'success', 'message': last != version})
diff --git a/polls/views/download.py b/polls/views/download.py
deleted file mode 100644
index 0ccf0b3..0000000
--- a/polls/views/download.py
+++ /dev/null
@@ -1,17 +0,0 @@
-import os
-from django.conf import settings
-from django.http import HttpResponse, Http404
-from django.shortcuts import render
-
-def app_intro(request):
-    return render(request, 'polls/app.html')
-
-
-def download(request):
-    file_path = os.path.join(settings.MEDIA_ROOT, 'pom.apk')
-    if os.path.exists(file_path):
-        with open(file_path, 'rb') as fh:
-            response = HttpResponse(fh.read(), content_type="application/vnd.android.package-archive")
-            response['Content-Disposition'] = 'inline; filename=' + os.path.basename(file_path)
-            return response
-    raise Http404
\ No newline at end of file