Glympse is an app that is free and does live tracking, but it will only do 4 hours at a time and doesn't show a complete track going back hours if that's what you want.

The Wahoo ELEMNT/BOLT have livetracking, but it is also dependent on cell phone coverage.

I have friends who were using the Sram Quollector during the dirty kanza -- but as far as I can tell it requires a subscription, is based on cell phone coverage, and is not actually available for purchase in north america yet. https://www.dcrainmaker.com/2016/09/...or-review.html