Foundation for Apps is a framework you can use to build better, more polished single-page web applications that work across many devices. We’ve taken what we’ve learned from building the original Foundation framework to build an entirely new framework just for web apps.An excerpt from Foundation for Apps
Foundation is one of the two most popular responsive frameworks for websites (along with Bootstrap). Now it sites alone as the first front-end framework created for developing fully responsive web apps. Built upon flexbox, using Angular and a new range of motion classes for animations you can start prototyping web apps quickly.