Power Flarm is used in the USA, and people often shorten this to Flarm, but it is different than the Flarm used in the rest of the world.

ADS-B is useless in gaggles beyond telling you that there another glider in the gaggle. Power Flarm is useful in gaggles because it filters spurious proximity warnings.

ASB-out makes me visible to power pilots who're looking at their screens. I was once thermalling and overheard Flight Following warn a power pilot that I was on his 12 at same altitude, two mile. He continue to close, one mile. He finally said, 'I still don't see the glider, but I have him on ADS-B, diverting."