Osm Contributor is described as 'The Openstreetmap Contributor app allows anyone to contribute to OSM. It enables those-who-know to easily manage a group of newbies as the contribution process is intuitive and easy. Bring your MapParties to a whole new level!' and is a Map Service in the Travel & Location category. There are nine alternatives to Osm Contributor for a variety of platforms, including Online / Web-based, Android, Mac, Windows and Linux. The best alternative is StreetComplete, which is both free and Open Source. Other great apps like Osm Contributor are JOSM (Free, Open Source), iD (Free, Open Source), Osm Go! (Free, Open Source) and Vespucci (Free, Open Source).
Osm Go! is a Android application and a Progressive Web Applications for contributing to OpenStreetMap. Map your environment simply and fast, directly from the app. Keep your eyes wide open and contribute to OSM while on the run.
Vespucci is the first OpenStreetMap editor for Android, Codename "Vespucci", continuously improved and developed since 2009. It supports the full OpenStreetMap data model including lots of less known quirks and can be used, if necessary, completely offline.
MapComplete is an OpenStreetMap viewer and editor. It shows map features on a certain topic, and allows to see, edit and add new features to the map. It can be seen as a webversion crossover of StreetComplete and MapContrib.