streetcomplete is a great companion app. It makes it really easy to add points of interest and help collect other data. I've already made over a thousand edits using it.

Yes yes. It's so satisfying contributing to OSM and seeing my changes pop up in OrganicMaps knowing it might help somebody and support open mapping data. I wonder if Wikipedians feel that way.

The Humanitarian OSM Team is cool too https://www.hotosm.org/