If AliveCot can sell this in the UK, I don't see why the delay for Apple to allow UK users to make use of the feature on the S4:
https://shop.gb.alivecor.com/products/kardiamobile
I bought a Kardia more than a year ago, and there are no restrictions on the ability to purchase them here. I found it odd when they said during the keynote yesterday that the feature of the Apple Watch is the first of its kind...
Possibly because Apple want a device that’s approved and accepted by the medical authorities before it goes into the wild so that the ECG results can be relied upon by doctors rather than being just a guide for a user ? I’m not saying that is the reason but as an outsider that’s my thoughts