[jrockway]

Haven't tried it. I only sleep with my phone in the bedroom when I'm oncall, otherwise, whatever the phone wants out of me can wait until I wake up.

If it works based on sound, that won't work either, because I sleep with air cleaners running on high in the room (and earplugs).

[kedean]

SleepCycle is accelerometer based, actually. You put the phone next to you or under your pillow, and it tracks your motion based on vibrations in the bed. I believe the app tells you flat out that it won't work on memory foam beds.