Hangtime has beacons too.

Yes. I have actually found that the best mounting location is on the top tube using something like the wrist mount in the link below. This kind of mount is very secure, keeps the phone in a safe location and out of the way while still visible during the ride.

https://amazon.com/gp/product/B0711MB5NW/

Cool, I'll try this out tomorrow with an old phone and some voile straps.

By the way, there is a "demo ride" available with the app download if you want to try the app but don't want to record your own ride.