I use Sleep as Android to track my sleep, it connects to my smart watch, but also can use sonar (yes actual sonar from your phone’s microphone/speakers) to track movement from your bedside table.
The best part of the app is it has “Smart Wakeup Periods” which let you provide a timeframe before your alarm that you’re happy to be woken up in. It’ll then wake you up when your sleep is lightest to avoid the groggy feeling of being woken up in deep sleep that normal alarms provide!