We wanted to enable college students and other travelers to have a better way to find places to travel that are within their budget. To accomplish this, we build an iOS application (and frontend web interface) that allows users to give their departing airport, desired dates of travel, and maximum price for a flight and we give them a list of flights to different places that are within their constraints.
We were unable to find an API that would accomplish this for us, so we build a Node.js web service that constructs urls to get airport fares JSON from Skyscanner. For the iOS app, we used Ionic to build an app that could easily connect with our backend and has cross-platform capability. The frontend web app used Angular.js.