HI Raj,
mainly there are 2 category of apps that can be developed using SUP.
1. Hybrid web container App: this is platform independent app. To develop this you need basic knowledge on JavaScript and HTML.
2. Native App: platform depedent.
here, if you want to develop apps, you need to have knowledge accordingly as platform variation.
for IOS >>> objective C
BB >>>> Java
Android>>>Java
Windows/windows mobile>>>.Net
you can find lot of information @ http://scn.sap.com/community/developer-center/mobility-platform
Regards,
Jitendra
