[AC Question]

I am using note 3. There is application 'MWStarter' which is displayed as arrow button on screen and works as drawer when tapped. It is also displayed while watching videos or any pdf.
I have force stopped the app, cleared the data, but it automatically starts itself and button is displayed again on the screen

[steezytech]

can you delete/ uninstall it? if not just go into your file manager and changenit to show hidden files. try and find it and delete the files. last resort root and flash Darkwolf ROM which id reccomend highly as it gives you both s7 edge and note 5 features. :-)

[AlphaTango414]

Can you long press the arrow icon and remove it from the screen? When it opens, does this open up for multi window operation?

You can try to look in your app manager and see if it can be unintalled or at least disabled.