don't bother with the app it doesn't work my Microsoft Lumia has been doing that for months now but more frequently in the last 2wk I just think there's a glitch in the phone which they've not a clue how to fix I won't ever buy another Microsoft product again never had any problems with apple

I am also using Lumia 435 I have also this problem only but I want to that how my phone

Hey there guys! Try using this app Microsoft released: Stop Restart App (link)

I have same problem.