Its working on z1 stock kk 4.4.4, just the usual bugs as identified in the main thread (like no pause->play button change when pressed, although player is paused)
For the first time to make music buttons in navbar to pick up the player, play from the music player (i use walkman, so i dont know if it will work on 3rd party apps) and then after that, you can play directly from navbar softkeys
Disclaimer: this s NOT my work
so make sure you thank the dev if you love it.
If not, thank anyway