https://gadgetbridge.org/
- https://github.com/mjsir911/gadgetbridge (mine)
- https://github.com/mormegil-cz/Gadgetbridge/tree/garmin-wip
They're also on Matrix: https://matrix.to/#/!KlgIJeiotNGZkxSqRi:matrix.org
https://codeberg.org/Freeyourgadget/Gadgetbridge/
In fact I'm still using it, from my Mi Band 3, to the Mi Band 4 and now the Amazfit Bip.
The folks behind it are doing a great job, and I'm glad they're doing it.
https://gadgetbridge.org/