[larkeith]

Uses, or should use? On an Android device (S5) I've found the battery usage from music playing not-insignificant - perhaps it prevents the phone from fully entering standby, or something? At a very rough estimate, I'd say it uses 20% as much power to play music as active usage requires, though this is very much anecdata.

Either way, I'll second the recommendation to get an external battery pack - a high-quality one will give more audio playback time than a media player, with much more utility and convenience.

[izacus]

Most modern phones (not sure for S5 which is pretty old these days, but Nexus 5 was the first to introduce it) have a separate DSP for music playback.

The app must use Androids playback API though.