I found a Camera app on Fdroid that is nifty for documenting changes. While taking a picture you can have a transparent overlay of another picture to align. That lets you make the "same" pictures at different times and compare them for new (or missing) things. Use VES for conpare, it can alternate pictures so the differences blink.

https://www.f-droid.org/packages/org.jshobbysoft.cameraalign/

https://www.f-droid.org/packages/com.vincentengelsoftware.vesandroidimagecompare/