StreetMeasure is an app to measure distances and heights. It is based on the non-free Google ARCode and thus was separated from the otherwise free/libre open-source StreetComplete a.o. in order to have the latter available at F-Droid.org – and also to make it your choice whether you're willing to accept a non-free component while remaining able to use StreetComplete no matter how you decide.

StreetMeasure was made for usage with StreetComplete and other OpenStreetMap editors. But you can use it