Operating system from Apple named iOS was primarily designed for iPhone mobile phones, but with time it begun to be used also for iPad tablets or iPod Touch and other devices.
iOS is a lite version of the Mac OS X operating system used in computers. It is a UNIX-based system and since it is designed for mobile devices, it does not contain the whole functionality of the OS X. But, on the other hand, it supports touch control.
Digital content (music, books, videos, podcasts) can be downloaded and purchased via iTunes service. A large amount of applications for iOS can be downloaded from App Store, which is a store with all various applications from Apple. If you want to download an app from the AppStore, you will need to register first. Registration is free and over 1,000,000 applications will be waiting for you there, plenty of them designed for iPad tablets.
iOS Mobile Apps Development
In the past, applications for iOS could only be created in xCode (development environment from Apple). Nowadays, it is possible in iOS to run apps created in C language or more advanced Objective-C. Besides own Cocoa Touch framework is available, XCode integrated development environment (IDE) based on Mac OS X and other tools for developers.
Development of applications for this system is relatively challenging and if you do not have capacities for it and yet would like to create an application, you can contact developers who directly work on mobile application development.