- Cross platform mobile app development allows building apps that can run on multiple operating systems like iOS, Android, Blackberry etc using a single codebase. This is done through frameworks like PhoneGap that allow using web technologies like HTML, CSS and JavaScript but also provide access to device capabilities via plugins. - While cross platform apps offer benefits like being cost effective, there are also challenges around performance, differing platform capabilities and the need to test on multiple platforms. PhoneGap Build helps address issues of working with multiple platforms and SDKs. Developers are advised to take a multi platform approach and be ready for emerging platforms.