Mobile computing, whether it is the ubiquitous laptop, smartphone or tablet, has become a necessary part of our lives for both work and play. Currently, smartphones and tablets have dominated the market, even surpassing personal computers and laptops. The three main companies that develop the operating system used by software developers to give us the ability to send, receive and process data on the go are Apple, Google and Microsoft. Technology is constantly evolving. These companies develop, with the help of other partners, hardware, operating systems and programming solutions that allow us to free ourselves from our desks. Their efforts also offer individual developers the opportunity to develop games and apps, with the added benefit of selling them in an online marketplace. Below is an overview of the mobile computing operating system architecture, programming tools, and online app stores that developers can use to distribute their work. Apple's iPhone, iPad and iPod touch all use Apple iOS (operating system) which is based on a tiered architecture consisting of four layers, cocoa touch, media, core services and core operating system. Most iOS development is done with frameworks that provide developers with the interfaces needed to program apps. The cocoa layer is responsible for defining the look and feel of your app, providing touch-based input, and many other high-level system services. The multimedia layer allows programmers to add high-quality graphics, audio, and video to their apps. This layer also allows developers to create media streaming apps. The Core Services layer defines the basic types used by all apps and support for features like iCloud, social media, and network services. Finally, the core O...... middle of paper....../features/android.html http://www.zdnet.com/blog/burnette/how-android-works-the-big- picture/515 http://developer.android.com/distribute/googleplay/publish/register.html http://developer.android.com/distribute/googleplay/publish/console.html https://developer.apple.com /library/ios/documentation/miscellaneous/conceptual/iphoneostechoverview/Introduction/Introduction.htmlhttp://www.zdnet.com/blog/burnette/how-android-works-the-big-picture/515 http://www. jetbrains.com/objc/ http://www.jetbrains.com/idea/features/android.html http://www.zdnet.com/blog/burnette/how-android-works-the-big-picture/515 http://developer.android.com/distribute/googleplay/publish/register.html http://developer.android.com/distribute/googleplay/publish/console.html https://developer.apple.com/library/ ios/documentation/miscellaneous/conceptual/iphoneostechoverview/Introduction/Introduction.html