Titanium, for cross mobile platform apps
Native & Cross platform
Making a mobile app is probably not very hard, but making a cross platform mobile app could be very hard. Titanium is one such open platform you can use to build the cross platform mobile app. Titanium is developed by appcelerator, which was founded by Jeff Haynie and Nolan Wright. It is mainly used for building iPhone/iPad and Android native apps.
Titanium binary can be also run on Mac, Linux, and Windows. It also provides various training materials, tutorial videos, documentation, and getting started guide. Titanium is fully open source under GPL licence. Its source codes is available on appcelerator GIT page.
If you are also interested in the showcase, there are many application out there developed by Titanium. Among them, the notable ones are Ebay, High Five League, and Jersey Shore Yourself.