Test watch face in progress on device as complement to simulator

In the Programmer's Guide that's included with the SDK, there is a section called "Side Loading an App", which shows you how to do this.

Basically, what you do is build the .prg and put it in the \garmin\apps directory on the watch itself.

One thing you can't do with a sideload is test app-settings from Android, iOS or Garmin Express, so you want to have that tested in the simulator.