This document provides an overview of mobile application development. It discusses the different platforms for building mobile apps, including native apps built for a single device platform and HTML apps that can work across multiple devices. The document outlines the typical process for developing a mobile app, including analysis, planning, design, development, quality assurance, delivery, and marketing. It also provides a demonstration of using PhoneGap to quickly build a basic mobile app using HTML, CSS, and JavaScript that can be deployed to both Android and iOS devices.