how prevent to uninstall the program ?

Dear customer,
If you mean simple Kidlogger for Android, or Kidlogger PRO, you can install another application, which prevents the user from The launching of Settings application.
We provide Patental Time Control application for Android, With this program you can disallow a user to launch some applications, inclusive the Settings of the phone.
For more info:
http://kidlogger.net/blog/parental-time-control-for-android.html?lang=en