What you do if you get a negative review?

[anush]

First thing to do will be identifying the problem that is causing the bad review. Fix the problem. And than relaunch the app with a newer version.

I agree that we should relaunch the app after fixing the problem and if the problem is small then just fix it and let know the user through comment that the problem has been fixed. In this way you will increase the authenticity of the app.