Have a look at eLyric. It will play FLAC directly (no transcoding/quality loss to MP3). I got it because I got the PS Audio PerfectWave DAC & Bridge and eLyric is a PS Audio product and the recommended controller for the PW DAC. I use eLyric as a controller, but it also works as a player. I have no experience with any of the apps previously mentioned in this thread, but eLyric is the best of all the controller/renderer apps that I have tried on Andriod and iPod/iPad.
J.P.
J.P.