Mobile application development is a term used to describe the process involved in writing software for small handheld electronic devices. These applications are specifically developed for use on mobile phones, tablets, PDA's and hand held game consoles.
Mobile applications are developed/created to run on a variety of mobile platforms. Google's mobile platform is Android, Windows uses windows mobile, RIM uses Blackberry and Apples mobile operating system is called IOS.
Once developed, these applications can be pre-installed as a part of the manufacturing process or offered separately for individual use. Mobile applications are generally developed to utilize the unique features that an individual mobile device offers.