Like apps and websites such as HowOld.net and TwinsOrNot.net, the Fetch! app scans and analyzes a photo of a dog from the iPhone's camera app or camera roll:

You start with your dog, or your friends' dogs. If the dog's breed is unknown, the app will show a percentage of the closest breed. Tapping the percentage rosette leads to the top five breeds that could be in the dog. Clicking on the arrow in the corner leads you to more information on the breed.and