App brings user to a driver.
Driver commutes to work everyday but has empty seats. He offers rides from 2 points along the drive to his work for a user or driver created price.
Both the user and driver have the ability to create the price and time.
App charges $x on any ride under $y and adds 10 percent for anything over.
Suggests $3x is the price.
Notes: Github is full of these kind of apps but they need a few tweaks to the above details.