Connect your headphones and music will start to play.
Just that simple and usefull.
Because it is great that music stops when you disconnect your headphone now you can enjoy to connect them and music will automatically start.
And the best: it's free!
You do not even need to start it. It will start with your phone after the first time you enable it.
You would not need to set it up never again. It will behave like a part of Android.
IMPORTANT: the app must be started at least once after the installation in order to start its service and configure it to automatically start every time the phone is powered on. It will not be necessary to start the app again.
If you have a problem with AutoPlay, please, read the guide to problem solution:
Note for Samsung users: currently Samsung Music Player Player always captures "play commands", so no other music player will work with AutoPlay. The bug has been already sent to Samsung.