Totem is a lucid-dreaming aid for Garmin watches. It tries to detect likely REM sleep using simple on-device heuristics and delivers a short vibration cue. If you condition yourself to associate that cue with doing a reality check, it can act as an external trigger for lucidity. Because Garmin’s native sleep staging isn’t available live to Connect IQ apps, Totem does some heuristic-based stuff to try and guess if you're in REM sleep: Time Lock: waits a configurable number of hours after you start the session Motion Atonia: low movement suggests stillness HR Volatility: erratic heart-rate patterns can coincide with REM Wake Guard: rejects patterns that look like you’re awake Work-in-progress; thresholds and behavior may change as the heuristics improve. Open source: https://github.com/jake-sager/totem Check out the README for a lot more detailed info!