Wife has a 4S, I have a GS3. I am looking for a good chat/IM solution that works well between BOTH iOS and Android. I've tried: Google Talk: Works great on android, always signed in and running in the background. Can use on PC/phone seamlessly. On iOS we've tried Vtok but it does not stay signed in. iMessage: No support on android. Google Voice: Apps need to be manually refreshed, a bit of a pain. No photo support. Is there any app that uses a non-proprietary message system and stays signed in on both?