BACK key emulation for non rooted phone (only Android 4.1 and later)

Install ToolBox.(test version)
https://dl.dropboxusercontent.com/u/84343930/ToolBox1.1.apk

  *The official version is here.

Setup Accessibility.


Select ToolBox and turn on.

Message from ToolBox will be displayed.

Select ToolBox via shortcut action.

Select 'Back key' from 'Function'. Then tap 'OK'.

That's it.