To me, it seems like this (the ? ) is the strongest feature of the app. My kneejerk reaction is that if you go to a place often enough to save it, you probably don't need directons anyway (or won't after one or two trips).
Nitpick aside, this is a beautifully simple interface.
I would guess that the most common use case is getting from the current location to a new destination (?). What if those 2 were more prominent? Saved locations could be an additional option but to make this more efficient, I would bring those 2 options to the forefront.
Nitpick aside, this is a beautifully simple interface.