My parking lot at the office is first come first served, so I end up parking on a different level (and on a different side) every day, and can never remember which.
My ideal app would allow me to configure it to just the number of levels in my garage, with an option for "side" (i.e. east v. West).
So, I would set it up to only show
P1W P1E
P2W P2E
P3W P3E
I could select it with a single tap, and it would clear itself at midnight (so it doesn't accidentally carry over).
There are apps out there, but they try to do far too many things, and therefore the simple one-tap convenience of it is lost.
(I was actually considering making a keychain fob to do this, and practicing my 3D design and printing skillz in the process)