I'm using Poweramp since about three weeks now and I'm preatty impressed!
But there is one thing wich prevents me from buying the full version: I'm using the player only in my car where I connect it via bluetooth to the cars audio system. Unfortunately the player doesn't provide playlists, folders, Song-List and so on... So I can't scroll through the songs or search for songs using the interface of my audiosystem in the car and I have to use the phone instead. The stock mp3 player from my phone provides everything. So am I doing something wrong or isn't that feature availab