Well... I didn't find it in time.
My Regular ring, despite rolling, sliding, changing to all possible orientations known to man, including turning the ring inside-out (ok, joking on that part)..
... I've gotten no acknowledgement whatsoever from my Nexus 7 & Moto X (all cases removed, etc..).
Other tags seem to work fine.
I don't know if I just need an Alpha, or if there is something wrong with my ring.