Add MAPS.ME cross-platform mobile app.

README.md

@@ -792,6 +792,7 @@ See also [awesome-gis](https://github.com/sshuair/awesome-gis).
 - [OpenGTS](http://www.opengts.org/) - Entry-level fleet tracking system. Supports variety of tracking devices and protocols. Comes with rich web-interface and reporting features. ([Demo](http://track.opengts.org/track/Track), [Source Code](https://sourceforge.net/projects/opengts/files/server-base/)) `Apache-2.0` `Java`
 - [OpenStreetMap](https://www.openstreetmap.org/) - Collaborative project to create a free editable map of the world. ([Source Code](https://github.com/openstreetmap/openstreetmap-website)) `GPL-2.0` `Ruby`
   - [CityZen](http://cityzenapp.co/) - Privacy-respecting Android app that helps you find Points of Interest ("POIs") such as ATMs, gas stations, etcetera, based on your location using OpenStreetMap. ([Source Code](https://github.com/CityZenApp/Android-Development)) `MPL-2.0` `Java`
+  - [MAPS.ME](https://maps.me/download/) - Offline maps application for iOS and Android, built on top of crowd-sourced OpenStreetMap data. ([Source Code](https://github.com/mapsme/omim)) `Apache-2.0` `C++`
   - [OpenStretMap Automated Navigation and Directions (OsmAnd)](https://osmand.net/) - Offline mobile maps and navigation app [for Android](https://f-droid.org/packages/net.osmand.plus/) and iOS clients with further online capabilities. ([Source Code](https://github.com/osmandapp)) `GPL-3.0/MIT` `Java/Objective-C++`
   - [OSM Contributor](https://wiki.openstreetmap.org/wiki/OSM_Contributor_Mapping_Tool) - Easy to learn Android application for individual users to add or edit data in OpenStreetMap's database. ([Source Code](https://github.com/jawg/osm-contributor)) `GPL-3.0` `Java`
   - [StreetComplete](https://wiki.openstreetmap.org/wiki/StreetComplete) - Gamified interface that offers "quests" to correct or complete data in OpenStreetMap's database. ([Source Code](https://github.com/westnordost/StreetComplete/)) `Java` `GPL-3.0`