Just struggled through a problem with the Sonos App for ios and android. It was intermittently freezing up for the customer. Usually you could cause the error by pressing the phones home key to put Sonos in the background. When it was accessed again it would be completely frozen. Tried a new iPhone with a basic install, and my own android phone from my home system. Turned out to be a Airport Time capsule with WiFi problems. Difficult to know what was wrong with the wifi and it was misleading because it usually would not freeze unless you pressed the home button or the unit went to the lock screen. Rebooting the router would allow it to work for about 20 mins then the problem would re-occur. Narrowed it down by bringing my own cell phone with the Sonos App and connected to their network and even my phone which I knew worked fine on my home system would freeze. Talked to Sonos about it and although a complete lack of Wifi will cause the app to display the Turn on Wifi message, a problem with the Wifi on the router where it is having trouble communicating consistently can cause the unit to hang. Hope this helps. It drove me crazy for about 3 days.