We should testing for our application<->service pair (application is freeware). So, we don't know IMEI list (because we don't know user-list, there are about 2-3 new users per hour). And there are up to 3 new application versions per day (bugfixes and so on)...
Application is unstable and users know it (to join this test-area user must sign agreement).
Application uses system capabilitys (same as SIPExample).
So, we can't use Open Signed Offline (because we don't know exact IMEI-list), we can't use Express Signed (because new releases it too often and application is not stable). User can't use Open Signed Online, because he can hav't PC and/or internet connection.
How to sign application in this case?