For Apple Watches the app for Tymewear is powered by the Tymewear App on your iPhone. The Apple watch needs to be in range of your iPhone during an activity to receive and display data. 

Setup
On your iPhone, open the Apple Watch App and then add the Tymewear App. 

This allows the Tymewear App from your iPhone to send realtime data to your Apple Watch. It also enables your Apple Watch to send GPS data to the Tymewear App.