4K Solutions and ToughStump Technologies offer training for ATAK. From their site:
ATAK is a mapping engine developed for the Android Operating System which allows for precision targeting, intelligence on surrounding land formations, navigation, and generalized situational awareness. ATAK is under continuous development by various government laboratories to include the Air Force Research Lab, the Army Research Laboratory and the Defense Advanced Research Projects Agency. It enables users to navigate using GPS and National Geospatial Agency map data overlaid with real-time situational awareness of ongoing events. The ATAK software represents the surrounding area using the military standard MIL-STD-2525B symbology for iconography and the Cursor on Target data format standard for communication.