Getting unwanted message "There are trespassing signs. Check it in Observer Settings screen." There are trespassing signs. Check it in Observer Settings screen.

I am getting the above message whenever I open a new app on my Android 4.1.2 Samsung Galaxy Grand DUOS. This has started suddenly when my child was just playing a simple ABC kind of rhymes.
Following things have been tried by me, in the given order, but without success:

Check out which was the last 3-apps installed and uninstalled them
Cleared App-cache
Did a restart

Any pointers or solution is welcome.
It is caused by the app Smart App Protector that maybe you installed and activated an option called Observer. Just check the observer and watch who wanted to enter your apps.

Good luck.