Tuding (or thumbtack) released the Windows phone 7 version of its No. 1 social photo sharing app, making it the first one of its kind to cover all major smartphone platforms including iOS, Android, Symbian and BlackBerry. The app to date boasts a user base of more than 4.5 million in China.

WinPhone 7 version of Tuding catered for as well as leveraged on Windows Phone 7 OS’s design concept, you can hands-down notice the differentiation in its app interface (pictured below), which patently borrowed Windows Phone 7’s Metro design language.

Except for the facelifting, what’s under the hood is still as strong as its other counterparts, the core 21 filters, location tagging as well as photo sharing among the most popular Chinese SNS including Sina Weibo, Renren, kaixin001 and so on.

Photo sharing has always something hot among Chinese startups and entrepreneurs, we’ve seen so many similar apps like Kaixin001’s Tuteng (Android and iOS). It is estimated that in the future 90% of photos would be shot by mobile devices. The saying is strongly evidenced by the fact that iPhone is the hottest photo-taking device on Flickr. The market is huge, and the ultimate ruler is yet to stand out from its peers.