FAQ section :

>Is is compatible with iPhone 4 ?

iPhone 4 S. 5C. 5S. Not iPhone 4.
(Bluetooth 4.0 Low Energy required)

>If my card is lost ?

Noone can use your card without knowing its PIN code.
You can recreate your lost card by intializing another card with the backuped seed of the lost card.
You'll be able to regenerate all private keys.

>If i want a backup card ?

You can use the backuped seed to make a copy of another card.