Hi,
like some others already asked for more polar devices, adding support for their API might add support for quite a bunch of devices.
I have a grit x pro which only syncs some data back to fit for example. It has sleep tracking and heartbeat tracking but both isn’t synced to fit.
So adding their API would allow both to be used by sleep as android as well as fit, since sleep as android would sync it with fit.
https://www.polar.com/en/developers
https://www.polar.com/accesslink-api/#polar-accesslink-api