Your customers can now log in with a one-time code texted to their phone instead of typing a password. They enter their phone number, get a 6-digit code by text, and they're in. No more password resets for the folks who always forget.

Turn it on from the SMS Messaging page. It works whether or not you've set up your own store SMS number. If you have one, codes go out from your number. If you haven't, they come from the shared Kiva Logic number, so there's nothing else to set up.
Each code expires in five minutes and only works once, so it stays secure.