Every Door
A dedicated app for collecting thousands of POI for OpenStreetMap
...You'll see mapped shops around you: tap on the checkmark for any that are still there, and add shops that are not on the map. That's the entire process: you can keep your entire town up-to-date thanks to this simple editor. There is also a micromapping mode for verifying and adding benches and street lamps. And an entrance mode for adding building attributes and entrances, which are merged automatically into building contours.