There is a workaround for rooted phones, but I actually unrooted my phone (whole reason I rooted it didn't work out anyways so I didn't really have a reason to keep it rooted).
I find it to be quite fun. Also it links with the new Nintendo Account, which is tied to your NNID. You can log into your Nintendo Account with your NNID if you need to, so it is linked to that. It is weird that you can't add Wii U friends on it though.