hmm 2 top manufacturers devices that have no error reports for nfc functionality are more likely to have issues then a ring whos 90% of customers are unhappy angry or can not get it to work, makes perfect sense. The truth is if it does not work with every nfc enabled phone (thats not broken and can read regular nfc tags) then the item does not work. You can not sell a nfc ring and then say oh it may only work with phones that havnt been invented yet. Unless you say it works on this one device (like the shitty doomed samsung gear)
so far the ring does not work with the htc one and one m8, samsung s3, s4, s5, note 2, note 3, lg g2, nexus 4, nexus 5
the fact that its hard to read makes the ring unusable and pointless (it was advertised as being a quick secure locking method)
if you have to remove a case it makes the ring unusable and pointless (just completely stupid and impraticle)
the fact it does not work with 90% of the phones on the street and market make it pointless
in short the item is sold in a 'not fit for purpose' state and as such all backers should be refunded in full and the idea either shelved or actually developed into a working item before shipping.