Coin is made by a company that is based in San Francisco. It looks like a credit card but can store up to eight different cards that can either be debit, credit, gift or even membership cards. Coin uses an app and a card reader adapter for your smartphone to input all your cards into one. It uses a magnetic strip on the back much like a regular card but with a press of a button it can cycle through your cards and change the strip. Coin detects if you get certain distance away from it and will tell your smartphone with an alert sound if you accidently leave it behind. It does this using Bluetooth Low Energy, which is the same thing used in most smartwatches and fitness tracking devices. The device does not have a changeable or rechargeable battery, but the battery in the Coin lasts two years and at that point you replace the unit.
Coin isn't available yet, but you can get your hands on one next summer. The company has started a campaign through their site and is looking to raise $50,000. At launch it'll be available for $100 but early backers can get them for $50.