The Spot On app is a more robust mobile application offering additional features not available via text messaging. You do not need to initiate your parking session at a pay-by-plate kiosk when you use Spot On like you do to use extend by text. Extend by text also charges a fee every time you extend your parking session, but the Spot On app only charges a fee to initiate a parking session, which may then be extended multiple times without paying additional charges for each extension."