The TomTom Multi-Sport Watch collects a lot of GPS data when tracking your sports activities so eventually you need some way to upload that data from your watch. In addition to being able to sync the data over USB to a PC, the Multi-Sport Watch can also sync over Bluetooth with your smartphone like the iPhone 6s.
After you have installed and opened the App, do the initial setting required for setting up of the TomTom Multi Sport Watch account for the phone.
Later on go to Lets Get Started -> Watch. The TomTom watch will then become visible to the App. Tap on the App in your phone to start searching for the watch. Please make sure your Bluetooth is enabled while phone is searching the watch.
After you select the TomTom watch, you need to enter the PIN that you see on the watch.
Once pairing is successful, your watch will show it is Connected.
You are now ready to use the App to track your location, speed, etc. from the convenience of your phone.