I have this apple app called "Stereo Speakers" on two iPad2's running ios 5 and it works great to make a much larger stereo sound out of two idevices connected through bluetooth or wifi. Might be useful for people carrying iphones who want a little non-headphone music now and again, which must be a growing population out there. It also doubles the volume possible on what you are playing, but don't abuse that one. Despite some negative reviews I have had nothing but a positive experience out of this $1 app and I don't work for the app developer. Both iPads seem to be in perfect sync with each playing a single part of the stereo channel. It only plays a single song at a time and the song must be on both phones, but it is nice if you make a single song out of a playlist ahead of time.