There is GPS Recorder which can also convert to .gpx format which is readable by Modrana but I havent tried that. It doesnt have maps so it should use a bit less system resources (not loading maps etc.) However as fellow someplayer user I noticed that as well. Its very easy to interupt by doing other things. I now regulary use Open Media Player and the stutter is much less, the default media player was better at playing in background as well. Something to do with the player engine if I remeber correctly. I usually record music from streams and listen to it on the phone (offline) and the lower bitrate (128 or 96 kbit mp3 ) work fine I also noticed .mp3 uses slightly less cpu compared to .ogg when playing music of about the same quality