Smart alarm is not work. One day it showed "sleep efficiency 100%" when I slept only a few hours. On the day, it started the alarm not in a right time (in deep phase), in a next two days, the signal does not worked at all (checked using additional alarm clock). Reloading the application did not resolved the problem. It seems that alarm works good, when it set in nearest time, and may not work if set at few hours ahead. Pebble firmware 2.0.1 (V2R2).
xxald about LetsMuv for Pebble, v1.2.2