Small apps that do one thing well. No subscriptions, no bloat, no catch.
Plug in your phone, set an alarm, and go to sleep. If you get up early and unplug, the alarm doesn't go off. That's it. No more blaring alarms in an empty room because you forgot to turn one off.
The free version of PowerWake. Same idea: your alarm only goes off when your phone is plugged in. Get up, unplug, and the alarm stays quiet.