This module covers the application development lifecycle for mobile apps. The module initially provides an overview of mobile platforms and then looks at the application development methodology used for mobile apps, taking into consideration the limitations of the mobile device platform and the opportunities provided through GPS, orientation sensors and networking. During the development process, interaction design considerations are considered with regard to the interface technologies provided by modern mobile devices. This will incorporate different implementation features that can be applied to mobile device applications, and the different platforms and development environments available. The growing mobile application marketplace and its impact on mobile application development is explored.