Quickly scan a bar code and compare prices – with stores nearby or stores on the web. ShopSavvy is an app that uses the camera on your phone or tablet to interpret bar codes, telling you about a product and showing you where to get it affordably. You can shop online at stores like Amazon or pull up a map of brick-and-mortar stores near you selling the same product, complete with prices.

Maybe you're out shopping and want to do a quick price comparison. Maybe you want to buy another copy of a book you have at home so you can give it to a friend. Or maybe you just quickly want to compare prices for a particular good. ShopSavvy is a quick way to do all of those things, and is also easy to use. Just hold your camera steady and it will do all the research for you.

So, how does it work? Open the app and hit the "scan" button. Your camera will turn on and you'll see a box with a red line through it, like this:

Move your camera so the entirety of the barcode for the item you're trying to scan is included in the box, perpendicular to the red line. As shown above. Once it works you'll hear a sound mysteriously identical to that of a Koopa shell being kicked by Mario, but you'll barely have time to notice when your prices show up:

Yes, I scanned a box of peppermint tea. Yes, it was the first thing I saw lying around the house after installing the app. No, I can't serve you any right now, but if you were here I totally would.

Anyway, as you can see there's an image of the particular product below with both online and local prices. Tap the online button and you'll see all prices from sites like Amazon and eBay:

It seems like it works for just about everything with a bar code on it. I scanned food, books, and video games and got results every time. For example: video games.

The prices come up, as before, but I want to know where I can buy this locally. So I hit the local button, then click the map button at the bottom of the screen. I instantly get this map:

Now I know exactly where to go to find the game, and how much the game will cost me when I get there. What else could I ask for?

How many local results come up varies wildly, depending on the type of item you scan. This one proved to be particularly obscure:

Guess that's something I'll simply have to order online.

Download ShopSavvy for Android, iOS, or Windows Phone

Ready to install? You'll find the ShopSavvy app on Google Play; it's a free download. You can find the same app for iOS (iPhone, iPad and iPod Touch) on iTunes, and a version for Windows Phone on the Windows Phone Store. They're basically the same, just with interfaces native to their platforms. You're looking at the Android version above.

Read more about the app at Shopsavvy.mobi, if you're interested.

Conclusion

Some blame ShopSavvy and apps like it for a decline in local retail. They might have a point, but in many cases scanning a barcode with an app like this reduces uncertainty. How often do you consider buying something, only do not because you're afraid you might overpay? With ShopSavvy you can quickly check prices in a store and know that a particular deal is a good one. So it hurts retail only when local prices are too high, in my opinion.

But that's just one take – there are many ways to think about such apps, but it's hard to argue they're not nice for consumers. Let me know what you think in the comments below, and also feel free to point out other apps for scanning barcodes. Here are a few others we've highlighted:

• Scan: Simple Barcode Scanning for iOS and Android
• Red Laser: Barcode Scanner and Deal Finder for Windows Phone 7
• Google Goggles: Conduct A Search Using Pictures