Hopper

MONEY rated the most popular travel apps, then tested each to find which ones could save you the most money. The winners:

Travel + Leisure

This article originally appeared on money.com.

Hopper

Search for a route, and the Hopper tool shows you a daily breakdown of the lowest airfares. If your departure dates are flexible, you can save hundreds of dollars. The app will also alert you when the price drops.

Related: Explore the Best in Travel 2016

GasBuddy

Gasbuddy

Crowdsourced data on fuel prices nationwide. We found an average differential of 41¢ a gallon across five metropolitan areas. Use Gasbuddy before you return the rental car.

OpenTable

Opentable

Make a lunch or dinner reservation and earn points that can be converted to gift cards. Some restaurants offer 1,000 points, worth $10 (though the majority give you 100 points, or $1). OpenTable works at more than 33,000 restaurants worldwide.

Related: 7 Best Domestic Destinations

Booking.com

Booking.com

Booking.com links to more than 800,000 hotels with especially good deals (up to 50% off the list price) on same-day reservations.

Related: Best Frequent Flier Programs

Skyscanner

Skyscanner

Using data from every major airline (including Southwest), this app selects itineraries based on shortest layover, optimal departure times, and best price. Especially on overseas flights, Skyscanner often finds flights that are cheaper (by $100 or more) than you could on your own.

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