Microsoft site to make intelligent guesses face recognition and can use large amounts of data with smarter applications, is working behind the scenes to show off on the way. Supposedly, improve the app and use it as more and more people becoming more accurate, the data uploads learns with time.
A Microsoft blog you can read the technical nitty-gritty.
How-Old.net is not very accurate, but it is close, and it is getting better. It also (or if you are a stickler for the truth 28) 130 a few years shy of my real life, I think in 23 years.