Apologies if this is already a known issue, but, if you have a song playing (one that's been copied across to your phone, so running locally) and then open another application opens and plays sound, then rather than gracefully fading out the foobar audio, the audio will intermittently crash with a constant buzz until you kill foobar.

I can't reliably replicate it, but it last happened about 30 minutes ago while playing a song and my iOS timer alarm went off (was cooking at the time).

Other than that great app by the way

If it helps it's happened on Build 43 and 1.0.1 an I'm running iOS 9.2 on an iPhone 5S.