https://www.macrumors.com/2009/04/15/absalt-easywakeup-monitors-sleep-patterns-to-function-as-smart-alarm-clock/
'Absalt EasyWakeup' Monitors Sleep Patterns to Function as Smart Alarm Clock - MacRumors
Absalt EasyWakeup [App Store, $9.99] is a unique app that monitors muscle movements in order to wake users at the optimum point in their sleep...
smart alarm clocksleep patterns