The Army at Fort Benning has been using ATAK. Here’s a description from the AWAE Systems book, 2017:
The Android Tactical Assault Kit (ATAK) is a tactical SA
and C2 application developed by the Air Force
Research Laboratory (AFRL). The software application
runs on any Android
operating system using version 4.0.4 or later. It supports planning and executing missions; airborne operations; close air support; and medical evacuation requests. Users can plan routes and navigate with GPS and National Geospatial Agency
(NGA) map data, and gather intelligence. ATAK is
currently deployed to Special Operations forces.