It looks like StreetComplete is Android only. Does anyone have suggestions for a good iOS friendly alternative?

As far as using OSM - I highly recommend Organic Maps, it doesn't offer editing features but It's great to use, the maps are all downloadable for 100% offline use and open source. It was made by the devs behind the original maps dot me (before it changed hands).

https://organicmaps.app

https://github.com/organicmaps/organicmaps