Mobile phones have become the most commin way of acessing the web as of 2014 more than 70% of web searchs where completed on a mobile device. So rather than hoping that a customer will click a link you have more chance of a return customer returning if you have a app they can install so no search is needed to be done online.
Developing apps for mobile devices requires considering the constraints and features of these devices. Mobile devices run on battery and have less powerful processors than personal computers and also have more features such as location detection and cameras. Developers also have to consider a wide array of screen sizes, hardware specifications and configurations because of intense competition in mobile software and changes within each of the platforms.
Mobile application development requires use of specialized integrated development environments. Mobile apps are first tested within the development environment using and later subjected to field testing. Emulators provide an inexpensive way to test applications on mobile phones to which developers may not have physical access.
Mobile user interface (UI) Design is also essential. Mobile UI considers constraints and contexts, screen, input and mobility as outlines for design. The user is often the focus of interaction with their device, and the interface entails components of both hardware and software. User input allows for the users to manipulate a system, and device's output allows the system to indicate the effects of the users' manipulation. Mobile UI design constraints include limited attention and form factors, such as a mobile device's screen size for a user's hand. Mobile UI contexts signal cues from user activity, such as location and scheduling that can be shown from user interactions within a mobile application. Overall, mobile UI design's goal is primarily for an understandable, user-friendly interface.