MapComplete
★★★★☆
Similar to StreetComplete in that it lets you pick a theme and edit OpenStreetMap using a set of guided questions. It has a different set of features that it looks for and a different set of properties it’ll guide you through, so it can be worth using both. I prefer using MapComplete to tag things like electric vehicle chargers, for instance, because it includes all the connector types. Or tagging whether a cafe has WiFi and what the network name is. Or whether a restroom has paper towels, air dryers or something else. StreetComplete works better for tagging which streets have sidewalks, parking and bike lanes, or marking building types, levels and addresses.
MapComplete also includes the ability to upload images to Panoramax and post reviews to Mangrove. And it runs as a website in a regular desktop (or mobile) web browser or as an Android app. (Before they released the Android app, I installed the website to my phone’s home screen and it worked pretty well, if slightly less stable when interacting with the system.)
The main drawback is that it doesn’t highlight features that are missing information the way StreetComplete does. Sometimes I try to add info and find that it already exists. (Sometimes I’m also the one who added it however many months ago.) I also disables the setting to show questions one-by-one, because with more fields available, it’s more likely that the first one in the queue is something that doesn’t apply or isn’t easily discernable, while StreetComplete has a smaller set that’s well-sorted by visibility.
In short, MapComplete is often better for updating a destination, while StreetComplete is better for updating the paths along the way.
More info at MapComplete.