My most advanced app for Garmin, yet. It works only with full touch rectangle screens, currently that is only the Epix, unfortunately.
It derives it functionality from a full blown Android dialer app (this is the one: https://play.google.com/store/apps/details?id=eir.dialer3) and provides that functionality at your wrist.
The only video demo of that app in function is on a Sony SmartWatch device, so here it is: www.youtube.com/watch
Full description of the app is available on the link below, and I would be happy to provide any help through email or on this thread.
Garmin app store link: https://apps.garmin.com/en-US/apps/b6f1ee3e-7663-4177-b1ae-8ce641631684