The GTM file format (initials for GPS TrackMaker) was created for the GPS tracking application GPS TrackMaker, developed by Geo Studio Technologies Ltd.

The file format was developed for compact data storage and enhanced recording speed when compared to text formats. The files hold waypoints, track logs and routes as well as other information related to the screen display, background and grid color, waypoint text, user-defined text etc. Digitized images are also included in the .gtm file.