How to uninstall Button Savior (non root) from Samsung Galaxy Note 4
I would suggest trying to uninstall via adb. You'll need the following if you don't already:


ADB
Enable Developer options

After that, proceed as follows:


Find the package name of the application on your phone that you want to uninstall. The easiest way is to use Package Name Viewer, or in your Settings under Applications. 
Enable Debugging mode through Settings -&gt; System -&gt; Developer options -&gt; USB debugging
Connect your phone to your PC
Right click on an empty area in the Fastboot folder while holding the shift key, and click on “Open Command Window Here”.
Now in command window type the following command: adb uninstall packagename where packagename is the name you found earlier (usually looks like com.packagename.anotherthing)
As soon as you hit the Enter key, it will uninstall the App and show you Success in the command window.