Im using retrocam which is fun but doesnt have all the options i like. I like diff film, exposure and click anywhere to take stuff. I dont have a flash so stuff that has night settings works good for me. Im willing to pay a few bucks if worth it.
MIUI has a decent camera app. But you would have to install a custom rom(I'm assuming) to get it, or at least have rooted your phone. If you are looking for effects, don't do it through the camera app, do it after.