I'd only downloaded the HR Broadcast app or whatever it's called and just left it sitting there,
then I rode to work, it rained so I took the bus home, and while trying to watch the Tour and ride the trainer I realized I'd left my heart rate monitor behind too. I was stuck, then remembered this and tried it, and it worked great
Thank you
If anyone else is in the same boat, this works fine for when you don't have a heart rate monitor but do have a watch, just a heads up