Open-source Citymapper alternative

OsmAnd, short for OSM Automated Navigation Directions, is a map viewing and navigation application for mobile devices. It uses the free, worldwide OpenStreetMap database and puts particular stress on complete offline use, with preloaded map data, or economical internet usage.

Using the device's GPS, it provides routing with visual and voice guidance for car, bike and pedestrian travel. Navigation works online or offline, with turn-by-turn voice guidance, optional lane guidance, street name display, estimated time of arrival, intermediate points and automatic re-routing. You can search for places by address, by type such as restaurants, hotels or museums, or by coordinates. On the map it shows your position and orientation and can align the map to the compass or direction of motion.

OsmAnd is written in Java, and the app is distributed through Android markets and the Apple App Store. The repository lists its licence as other, so check the project for the exact terms, and community discussion takes place in a Google group.