Maybe you're itching to grab the family for a spontaneous weekend getaway. Or perhaps a cancelled flight means you need an airport hotel in a hurry. Or let's say you've been on the road all day and need an affordable place to stay along your route. Whatever your reason for seeking a last-minute hotel, the HotelTonight app can land you a super deal with just three taps and a swipe.

Hotel room prices fluctuate with supply and demand.

As the check-in date approaches and rooms remain unsold, many hotels drop their rates. By matching travelers with unsold inventory, HotelTonight can help you find a room for tonight or up to a week out, at more than 15,000 hotels in over 500 destinations all over the world.

The deals are indeed impressive, especially in major urban areas like New York City, Chicago, or Philadelphia, where the app regularly unearths rooms at centrally-located, family-friendly hotels for well under $200 a night.

But it gets better. HotelTonight just added two additional features that make finding a last-minute hotel even easier. Bonus Rate and Rate Drop rates are special, limited-time deals with discounts of up to 40 percent off the already-discounted HotelTonight rate:

• Bonus Rates are available up to seven days in advance in specific geographic areas
• Rate Drop rates are special same-day offers in certain destinations starting at 3 pm.

All hotels are curated by the HotelTonight team, categorized by style (such as Basic, Hip or Luxe), and accompanied by photos.