Nightjar
A sleep tracker and alarm for Android that records what happens in your room overnight, and only switches off once you've walked to a spot you chose.
Nightjar listens through the night and keeps a short clip of anything that stands out: snoring, talking, a thump. In the morning you hear what happened, labelled.
It wakes you inside a window you choose, at a moment you're already stirring. To switch it off, you walk to a spot you photographed, like the bathroom sink, and point the camera at it. The room goes silent while you do, so whoever is still asleep stays asleep.
No account, no subscription, nothing uploaded. Free and open source. Android only, in English.