Darn app almost deafened me

I dont know how, but the app somehow cranked my volume all the up without me knowing and played some weird tones. Well I didnt know it turned my sound up, so when I went into another app the music off it came blaring into my headphones. Im not even kidding when I say ,y ears are ringing because of it.

KBLively about Payanywhere: Point of Sale POS, v4.4