This app sounds awesome, wonder if anyone tested it with #GrapheneOS.
Device recommendation is here: https://gadgetbridge.org/faq/best-device/
(looks like no Gramin or other classical smartwatches are supported yet)
I also miss being able to use Google Pay (I know - it is all borrowed money) for which some of the best ones I was given:
Pixel watch - mentioned by the nostr:nprofile1qyvhwumn8ghj7un9d3shjtnddakk7um5wgh8q6twdvhsz9thwden5te0wfjkccte9ejxzmt4wvhxjme0qy88wumn8ghj7mn0wvhxcmmv9uqzpva683gyt7a0nxlfedx648ca0whwm2aql3dezkt9z830k7nsm4leqctypa account (hope it's the right one)
Garmin Instinct - with solar watch face serving for 2 weeks without charging in the summer, bigger the better.