Dear sir,
I think you dont have much idea about we chat. we also started to develop wechat modified IM app . but unfortunately wechat dosent allow us for developer account access. we tried 4 moths, but didn't get the approval, if you have approval then its find to start. you can test it form we chat admin console.
now we are using easymob API, but not have features like wechat, but fair enough for doing something.
if you want more details please contact me.
Thanks.
Namal