I have farm story on my S2 which after a long period of testing other apps and having my phone checked by samsung, I have singled out as the cause of my battery problems. After using it, if I manually go into the menu and "force stop" the app I'm fine but if I don't my battery drains three times as quickly. This has only been happening recently, in the past it would not cause this issue with my phone at all so I don't know if it's a bug or a new update causing this.

Some quick figures - if I manually "force stop" the app and I listen to music I get about 18 hours or so before I get to 20%. However, if i forget and use the music player, my battery dies within 4-5 hours!