I just saw that the remote control app is free at the moment (10,99€ off). Maybe only in the german store than you have to switch your iphone or what ever to german “Deutsch”.
If you are running trainerroad on a mac and have a iphone mounted to the bike this is just perfect. Before I had a mouse in my shirt and just clicking random youtube-videos. With the app you can controll volume and you got a mouse + keyboard. Should work with the new beta and the keys too - not tested.