how to download weichat to my iphone5 ?

not sure what weichat is but the only place to get apps into ios devices is app store

programs you see for download on webpages and the likes are not ios programs but likely windows program and the like

Eurobin wrote:

I want to download and install it to my iphone 5, what can I get it and how to have it installed, please?

If that is the same as tencent weibo, then it is part of ios 7. If it is not the same, then like Rudegar says, all you can do is search the app store directly yourself.