Like a song while playing and/or adding to a playlist (also in screenlock mode)
Next button in autoplaymode (optionally with choice of mix style e.g. brake, reverse, echo, flanger, delay …)
Adding the choice of a crossfade style (cut, hard, middle or soft) especially for autoplaymode
!!! Adding 3rd party clouds like soundcloud, google play music, iTunes match, Dropbox, Whimp, YouTube…(like you already successfully did with Spotify) without the need to download the songs before - real time streaming)!!!
Creating a djay solution for Windows as well