2. Priceline Mobile App

Priceline has long been a go-to site for savvy vacationers looking to save, but their Priceline Mobile App means that users can literally book hotels and rental cars minutes before check in. Perhaps inspired by Hotel Tonight, they also now offer Tonight Only Deals: Super-discounted, super-scarce deals which show up at the top of the list of available rooms. This app is available for both iPhone and Android.

Get the best deal on your car rental