I posted this on Discord, then Mailman reminded me we have an email list, so I'm repeating it here.

I know we have some OpenStreetMap contributors, so I wanted to give StreetComplete a mention:

It's an Android app that asks simple questions about nearby places. It then uses the answers to update OpenStreetMap. I've been using it for a few weeks and I'm very impressed. Simple to use, but adds lots of useful detail to the map.

Robin