Photo by Rick Broida/CNET

One of the coolest concepts I've seen this year is the Dimple, a plastic strip with four (or two) physical buttons that you stick to your Android device. It's powered entirely by NFC, and an app lets you program the buttons to do your bidding: run an app, toggle the flashlight, launch the camera, or whatever.

Sounds pretty cool, right? But I couldn't help wondering if the reality would live up to the promise.

Fortunately, the Dimple folks were kind enough to send me a four-button prototype to check out. I fished out my NFC-equipped Motorola Moto X, installed the Dimple app, and put the four-button strip to the test. (Alas, I wasn't able to test with a case, though the devs say it'll still work.) How'd it do?

For starters, it's a little tricky to know where to place the sticker, which is about the length of your pinky (well, my pinky) from the knuckle to the tip. And it turns out it can't go just anywhere. On the Moto X, for example, I wanted it near the upper-left corner of the back cover, which is roughly where my left index finger lands when I hold the phone. But the NFC signal wasn't strong enough there, so I ended up with it on the right side, just below the speaker. (Your mileage may vary; you'll want to experiment before removing the adhesive backing, though I was able to remove and reapply the sticker numerous times.)

Because the buttons are a little stiff, though, I couldn't just tap them. I had to give them a firm press, which requires a somewhat awkward adjustment of your grip if you're trying to one-hand it. I found it more comfortable to brace the phone with my right hand while pressing a button with my left.

Dimple

I actually think the two-button Dimple will prove more practical, as it should give you more placement and orientation options. A three-button version would make sense, too. As it stands, it's a bit tough to remember the programming for four buttons. (Let's see, was it Flashlight, Camera, Kindle, and Cozi, or Flashlight Camera, Cozi, Kindle?) That may just be my issue.

The app walks you through every setup and programming step, making both a snap. There's no pairing required other than enabling NFC on your device. And it's a thing of beauty that the Dimple requires no external power.

However, one small letdown: It doesn't function when your screen is off. It would be nice if a button-press could wake your device and perform its action, but on the Moto X at least, that doesn't happen. You have to tap the Power/Wake button before the Dimple can operate. I'm sure that's a power-management issue; full-time NFC would probably drain your battery more quickly.

The four-button Dimple will go on sale (online) in August for $27, with the two-button version following in September for $17. Again, I suspect the latter will prove more popular, both for its lower price and easier accommodation.

One thing is certain: the Dimple works as advertised, and it's a really terrific addition to any phone that supports NFC.