This is too biased for me IMHO. I do agree with some points, documentation IS amazing, and you are very likely under-documenting things. But documentation is not cheap to create, and specially it's not cheap to maintain. I've worked in multiple companies where the problem was too much documentation, and of course everyone was afraid to update or ghasps remove any piece of old documentation in case it... - Source: Hacker News / about 1 year ago

Haven, available either on F-Droid or Google Play. Source: about 1 year ago

Haven might be what you are looking for. It can activate sound and video recording upon noise, light and vibration. It is in the IzzyOnDroid Repo or has its own repo. Check the project page: Https://guardianproject.github.io/haven. Source: about 1 year ago

Haven is open source. Last updated 2019, but works. https://guardianproject.github.io/haven/. - Source: Hacker News / over 1 year ago

You could retire it to a personal surveillance camera with haven (needs a sim for registration though). With root, you could even set a charging limit so the battery doesn't die. Source: over 2 years ago

For budget option, you can install Haven on an old phone and it would record/report audio, visual and movement you need to monitor. Source: over 2 years ago