Coin Beta

Coin — the sort of physical digital that aims to replace all the other cards in your wallet — is now available for backers to claim. (We're one of them.) There are a few caveats, though. One is that while the iOS app will be ready Aug. 28, the Android app won't drop until Sept. 25.

Another caveat — and this one's a biggie — is that backers will need to pick one of two options. The beta route will get you more immediate access to the card and software, but with only 85 percent acceptance guaranteed. That means it might not work 15 percent of the time. You'll also be missing "Left-Behind Alert," which would warn you if you leave the Coin card (and thus all your credit cards attached to it) behind. And it won't be available internationally.

If you opt for the "Gold Standard," you'll see 100 percent reliability, Coin says, along with the left-behind alerts. But you'll have to wait until the Spring of 2015 to get your card.

So if you're a Coin backer, check your mail. And choose wisely.

More: OnlyCoin.com