Taptap.cn is a website for downloading games.
These games are mostly only available in China.
(Please note: you need an ID number and a phone number of the region in China to play some games because they are only released in China).
This app is the beta version which is quite different from the normal app.
You can either sign up via Google (email phone number doesn't matter from which country) qq wechat or you can just download games without registration just like that have fun.