VizAge is a slickly implemented app that estimates the age of a person from a captured portrait photo. It's fair to say VizAge has limited practical value, but it does have the potential to entertain, and, as such it's a great entry in what might be termed the "pub app" category. Good for showing off down the pub, or raising a few laughs at a party. 

The app works by using the APIs for Face.com (which was recently acquired by Facebook), which earlier this year added an age detection component. This services an estimated age, a minimum value, a maximum value and a confidence value (all of which are used in the app). It works by comparing uploaded photo faces to existing photo face with known age values and looking for certain characteristics. There's plenty of room for error, and the results do vary a lot from photo to photo, but the overall estimates aren't that bad, but it is worth noting that it's not as accurate as if a human does the guessing.

The VizAge app implementation takes a simple idea and puts it in an app with great design credentials; smooth transitions, well themed graphics, intuitive UI controls and decent performance, all add up to great user experience. 

The app guides you through the photo capture process, offering tips on how to get the best photo for an accurate age estimate. The age estimate process takes around 15 seconds (assuming WiFi or 3G connection), after which the app presents with the results, overlaid on the captured photo.

From the app's main menu you can view previous age estimates and their accompanying photos and there's also a clever extra "Celeb Ages" feature, which draws on a database of 300 famous faces and shows their age estimates.

Marketplace description:

Have you ever wanted an app that uses the latest face recognition technology to guess someone’s age? No?! Well, now you will!

VizAge is a unique and beautifully designed app that lets you take a picture of anyone’s face and it will attempt to guess their age using Face.com’s advanced facial recognition technology. You can then share your result with friends and compare it with our database of over 300 famous faces from the world of Cinema, Music and Television.

VizAge can be downloaded from the Windows Phone Marketplace. A free trial is available, which allows you try the app out on five faces. After that you'll need to buy the full app at a cost of £0.79 / €1 / $1. That's great value for something that should keep you entertained for a lot longer than a bag of pork scratchings.

So VizAge - the perfect pub app? Well almost, but bear in mind you may end up buying a round when VizAge doubles the actual age of one of your drinking companions (or that shifty looking bloke at the bar)... You've been warned.