Mobile App is an executable program, such as that designed for desktop or laptop computers, specifically for use on small wireless computer devices, such as smartphones and tablets.
Mobile apps are designed to meet the needs and limitations of small mobile devices as they benefit from the capabilities of these devices. For example, a mobile game may use an iPhone or Android device accelerometer.
In general, in terms of the structure and programming environment and how mobile phones are offered to the market, mobile can be divided into three main categories: Native Apps and Hybrid Apps or Cross-Platform and Web Apps
Native Apps is written in a specific environment with the same language. So for each device, it must be programmed separately. For example, an Android device provided by Google, Apple's iOS-powered device, Windows Mobile introduced by Microsoft, is now known as Windows Phone.
Hybrid Apps or Cross-Platform means that they write a program once in a particular environment, and then prepare it for different device environments such as Android, Apple, or Windows.
Web Apps, your website designing Responsive, is also appealing to the devices on the device. This model does not need to be installed, and since it is actually a website, it can be viewed on a browser.