Improve user experience of auto hiding nav bar

[117649]

Is it possible to leave some marks outside to mark the position of the items in nav bar while the bar is hidden?
Like this:

This would be very helpful when you want to locate the button you want fast while using the auto hiding nav bar.

[black7375]

How can I mark naturally?
Have you ever thought about it?

[117649]

A floating transparent mini icon of the actual button would be most natural for me.
But if a dot is all that can be done I'm also OK with it.