Feature idea: start recording on sound
Specifically related to fixed length recording, it could be very cool if loopy started recording after sound hit a certain threshold - and then recorded the exact measure count from there, not the loop start.
Cool for a couple of reasons. First, it would help with the 'I started a little late/early' thing by allowing for play through based on when you started, not the top of the loop.
Second, and this is what made me think of it, you could capture e.g. four measures of an app or source that supports tempo but doesn't support midi sync and then use loopy's sweet loop offset feature to line it back up. Capturing and aligning a DM1 beat, for example.