I have issues sleeping and walking up to an alarm. Found an alarm/sleep monitoring app last night that claims to be able to tell which stage of sleep you are in. It uses the motion and sound made by you at night to make this determination. (apparently you lay extremely still and quite during REM sleep and move around quite a bit when you come out of it)
The alarm function gives a +/- 30 minute window on the time you set and will go off when you come out of REM sleep. I used it last night and the alarm actually woke me up right away. First time that has happened in a long time.
Also with the app recording sounds and motion when you sleep it let's you hear what was going on when you were sleeping with a playback function. Sounded like some demons were visiting me in my sleep lol.
Even if you don't have problems sleeping/waking up it is interesting to see what's happening and there is an option to send the data in for research purposes. You need and Android or iPhone to download the app.
https://mysleepbot.com