Hipmunk
Hipmunk takes the agony out of flight search.
3 Alternatives To Hipmunk
HERE
HERE provides APIs and solutions to build location-aware web and mobile apps.
Skiplagged
Skiplagged is an airfare search engine for cheap flights, showing hidden-city ticketing trips in addition to what sites like Expedia, KAYAK, and Travelocity show you. Save up to 80% on airfare today!
Skypicker
Find and book the best low-cost flights all around the world