The coupling with the runtastic app worked immediately. Simply go into the Settings Runtastic on heart rate and there choose chest strap (as if you were an original Runtastic pulse belt use), and combine well.
I have used and in between sometimes borrowed my girlfriend with her iPhone 5 (iOS 8.3) the belt so far with my Nexus 5 (only Android 5.0.1 and now 5.1). My girlfriend also uses the runtastic app and there immediately was a coupling possible.
You just have to be careful when creating the belt. I had this only too loose set with my girlfriend and deeply attached, which has often led to short dropouts. The problem I had not been with me. So always best short attach below the breast in the area of the solar plexus, then it works without problems.
The Bluetooth range is also perfectly adequate. I put my smartphone ending the workout like to a few feet away from me and yet the connection remains active.
All in all I am very satisfied with the belt and do not regret that I have not resorted to expensive Runtustic belt.
