similar Android Open Source Apps (from more similar to less similar):

• SCEE (StreetComplete Fork with more features)
• OpenStop (dedicated tasks for public transport)
• EveryDoor (different concept mainly for POIs)
• Vespucci (full OpenStreetMap Editor)
• OsmAnd (Navigation with respect to data gathered by StreetComplete, POI search/adding/editing)

https://mapcomplete.osm.be is a website where you can easily update and add new points to OSM. It is my favourite (because I’m also the one making it).

Instead of seeing everything at once, you get to choose many thematic maps, depending on what is interesting to you (e.g. ‘shops’, or ‘restaurants’, or ‘cycling related stuff’, or ‘what is this street named after’, …)