Originally Posted by
Weston@HPTuners
Yes, TrackAddict will work without cellular service, and can operate completely offline. You also won't have to worry about phone calls interrupting your video recordings, etc.
The only places that Internet data is currently used is for the satellite background imagery on certain map displays, the Live Telemetry Streaming option, and of course app updates. If desired, all three would still be possible by connecting it to a WiFi hotspot provided by your normal phone, but that's optional.
Last time I was at the track, I used a non-activated Android phone running TrackAddict, and even had Live Telemetry enabled by having it connected to a mobile hotspot on my personal phone. It's pretty convenient to be able to leave a device mounted to the windshield all day without having to give up my primary phone to do it.