Since Apple v2.16 and Android v2.6 all you latest songs parameters (audio levels, pitch, tempo, difficulty, loops) are saved on your device locally and in the cloud.
It lets you pick things up where you left off. Switch to a secondary device or even migrate to a new one. Your song parameters are saved on the cloud when you are connected to the internet and close the player or open the app.
Currently only a single set of parameters can be saved per one song.