Stratos is not just another all-in-one smart card

The way it works is fairly simple. Up to three accounts can be loaded on Stratos at any given time, and you just tap the card twice to activate it. When the lights blink, press your finger to one of the three markings on the right side to select the account you want to use. If you forget which card is aligned to which slot, your phone reminds you which ones are which with a lock screen notification.

You can store an unlimited amount of accounts in the app, and it's as easy as dragging and dropping to swap which ones are loaded on the card. There's even a wildcard spot on the left that lets you use an account without changing one of your three regular slots. (Stratos says that users typically only rotate between three at the most.) That way if you have to access an account you don't typically use, or have a one-time use gift card, you won't have to swap out one of your most-used cards. It also offers smart recommendations that work very similarly to bluetooth beacons. Say you have a Starbucks card loaded; tapping Stratos on your phone will tell you whether there's a location nearby.

Stratos is being sold as a membership ($95 for one year or $145 for two), which CEO Thiago Olson says will let them add features along the way without making users buy a whole new card. That means that things like NFC, smarter recommendations based on location, and virtual card downloads — all of which Olson says Stratos is working on — could be rolled out to members when a new design is released. That membership brings support, too. The battery of the current card will last over two years, though, and the company can send a new card if a battery is dying.

Of all the startups that have tried to do this before — Plastc, Coin, LoopPay — the closest competitor to Stratos is probably Swyp, another all-in-one card that promises to replace every card in your wallet. Stratos has the advantages here, both in the design (it looks nowhere near as spartan as Swyp) and because it promises to reach the market by April. Otherwise it uses a headphone jack reader to add accounts to your card, just like Swyp, and has a similar Bluetooth security feature. To protect your information, the app can tell when the card is out of Bluetooth range, and after a pre-determined time — anywhere from 15 minutes to 24 hours — it can disable the card altogether. (Don't worry, the card will work again once it's back in range).

Stratos should also have an advantage thanks to the dynamic dual-stripe technology it uses, which Olson says should cut down on failure rates. It also means that Stratos should work basically anywhere you can use a card — the company promises "100 percent compatibility" from point-of-sale machines to dip readers. That last one has been a big problem for some of its competition, whose not-so-streamlined designs prevented them from working correctly in things like ATMs or, here in New York, MTA machines.

As for the competition with services like Apple Pay, Olson says that Stratos has two advantages. One is that there are still times where you won't want to hand off your phone to pay, like at a restaurant. The other is that NFC payments are still not available everywhere; Stratos members would be able to use the card in more places right away.

The biggest question here is how well Stratos will work. I didn't get to try it out in the real world when Stratos came to our office, but we'll surely put it through its paces when we get a working unit. This has been the most obvious failing point in the other services we tested like LoopPay and Coin, but Stratos seems to have a solution with a much better chance.