— system Android player (except 2.3 and above! It's system limitation, that I'm trying to resolve)
— system MIUI player
— system HTC Sense player
— system SGS2, Galaxy Note and Galaxy Tab players
— Astro Player + Astro Player Nova
— bTunes Music
— MortPlayer Music + Mort Audio Book Player
— RockIt (partially)
— RockOn (aka cubed, ³)
— NRG Player
— TTPod (full general version support, limited 'international' and 'ads' versions support)
— … more players later!
Unfortunately Winamp and doubleTwist players broke support for external controlling.
You can open the panel by long-press Search or Camera button (depending on preferences), connecting wired or bluetooth headset or using notification bar. Tap outside the app window to close. Use the Menu button to access the settings.
If you find any problem or have any question or idea, send me a email from settings or post comments in my blog (artroman.ru). I can't answer here in comments :(