Android Development
Android development is a design and programming process by which new mobile applications are created for the Android devices (mobile phones, tablets, etc.). You'll need Android mobile application if you need your system or website to work offline.
IOS Development
IOS development is a design and programming process by which new mobile applications are created for the iOS devices (Apple mobile phones, tablets, etc.). You'll need iOS mobile application mostly if you already have Android application, and you need your system or website to work offline by iOS devices.
Windows Mobile Development
Windows mobile development is a design and programming process by which new mobile applications are created for the Windows mobile devices (mobile phones, tablets, etc.).