Mobile - Add option to hide or move the "menu" button

[Lobuttomize]

When reading in immersive mode on a tablet, the menu button being in the bottom right, where my right thumb is most easily able to tap to turn the page, is annoying. I think, ideally, for me, I would like to be able to stop any UI elements from popping up unless I double tap to exit immersive mode.

 

[Lobuttomize]

Basically, the exit and menu buttons still function while hidden and that gets in the way.