You probably already know of it, but i will still recommend (for others) StreetComplete(F-Droid). Its a somewhat gamified osm editor that automatically puts lil flags all over the map around you for things that need fixing or updating. One example being opening hours, because those change from time to time so its useful to check sometimes if they are still correct. Another is accessibility things like "is there a ramp here" or "is there a railing for these stairs".