Plan months in advance or book your flight on the way to the airport. Either way, these apps make the experience faster and cheaper.

CheapOAir Flight Search

Not only is this app easier to use than CheapO's full website, it repeatedly delivered us fares that were $10 to $20 cheaper. Flights appear as mini itineraries with details about airlines and layovers. You can also search nearby airports and easily book multicity trips.

WIRED In-app promo codes for extra discounts. Email flight info to book it later.

TIRED No flexible-dates option.

Free ioses | Free androids | CheapOair Flight Search

Orbitz

If you're familiar with Orbitz.com, you'll know your way around this app immediately. You get simple search, filters like price and stops, and the same policy of no extra fees. Unfortunately, though, the app doesn't include the ability to search three days before or after your travel date or to include nearby airports.

WIRED Flight tracker to check the status of your plane.

TIRED You can't share flights via email. Missing some of the search customization tools of the full website.

Free ioses | Free androids | Orbitz

Momondo

Luckily, this mouthful of an app is much easier to use than it is to say. It aggregates deals from major airlines and booking services to give you flight options that you can filter by departure and arrival times, airline, price, duration, and number of stops.

WIRED Save searches for the next time you use the app. Share results—with price and flight details—via email. Automatically search nearby airports.

TIRED No flexible-dates option. No detailed layover info.

Free ioses | Free androids | Momondo

Kayak

Need to find a last-minute flight to Seattle? Want to convert currency, get a rental car, or survey the eateries at Reagan National? This app does it all. Its easy-to-use interface with authoritative, airport-sign-style icons should make you feel at ease planning your vacation on a smartphones.

WIRED Turn confirmation emails into an itinerary. Set alerts for notification when fares drop.

TIRED Doesn't show total cost for multiple passengers in results. Windows phones version doesn't get price alerts.

Free ioses | Free androids | Free WP Kayak

Hipmunk

Sure, Hipmunk lets you filter searches by price and departure times, but it's the "agony" filter—which factors in things like price, layovers, and duration—that makes this app such an essential tool for frequent or fussy fliers. Not a fan of purchasing via mobiles? Find your flight and use the provided code to complete the booking at hipmunk.com.

WIRED Syncs with your calendar to show potential conflicts. Notes flights with in-plane Wi-Fi availability.

TIRED Can't rank flights by on-time records.

Free ioses | Free androids | Hipmunk