Apparently Android has a Safe Mode you can boot into:
(1). For various android phones(LG, HTC one, ZTE or Motorola etc): hold down the power button to bring out the menu with Power Off and Reboot option—-hold down the Power Off option (If nothing happens, please tap and hold the Reboot option instead)—-click OK on the pop-up box asking if you want to access safe mode
(2). For Samsung Galaxy S4, S5 and Samsung Galaxy S6: power off the device—-turn on and tab the soft-touch Menu button repeatedly
(3). For Samsung Galaxy S3 and other phones with similar customized android system: power off the device—-turn on and hold down the Volume Down button (try Volume Up or Volume Down and Volume Up together if Volume Down does not work) when the brand logo shows up
You will see “Safe mode” at the lower left corner of the screen if you access safe mode successfully.
Then go into Apps and try and figure out which app is causing the problem. Get rid of any that you don't recognize. See:
for other options