The software allows one to read pictures of barcodes, which will then allow one to compare prices both in the real world and online, to find the cheapest prices. The software effectively turns your local BestBuy into a showroom for the products of the online world.
The software appears to work very well, with good recognition of barcodes, but at least on the front page makes rather bizarre use of the metro UI, with the front page consisting of a single page pivot, when Microsoft recommending a minimum of at least 3, and the software appearing to offer (annoying) helpful hits every time the camera is used to read a barcode.
Non-US readers will also be disappointed that the software only appears to compare US locations and websites, despite recognizing non-US products extremely accurately.
US readers can find the app in Marketplace, or by following this link here.