I use the instruction manual that comes with the app to figure out a lot of the issues and questions I had.
I know for sure you can swipe up or down on the right headphone to turn up or down the volume. Double tap to change songs and answer calls.
Not sure if it will allow you to play the previous song. That might have been one of the negatives I read about. I have mine connected to my new Hydrow and do not have to change songs, so I cannot remember if I was able to replay songs or not.
Sorry not more helpful, but I would double check the app for sure.