Thanks @Xan, we like the idea of a small wearable too. We’ll add you to the trial list!
@Xan and @AntMcAnt re security: we understand wearables are as safe as cards. The chip tech is the same level of encryption. Arguably wearables are safer because you never let them leave your possession.
Scanning an encrypted chip is effectively pointless. It takes more than a couple of scans to break the encryption.
Having a rogue merchant taking payments from your wearable is possible, but merchants are subject to quite arduous checks on application with a bank, so not easy. In any case in that scenario the bank of the rogue merchant would be liable to refund.
Losing a wearable is like losing a card. Once you realise it’s happened you can stop any further payments through your app. Any fraudulent payments would be refunded by your bank, pending your bank’s review.