The Degree Thesis in Computer Science focuses on development of Android applications to be used on a handheld device running the Android Operating System (OS). It covers the basics such as setting up a development environment, downloading appropriate tools and add-ons. The thesis serves as a guideline to intermediate developers, seeking solutions to problems not discussed in available textbooks. Android is a platform consisting of an operating system and a Software Development Kit (SDK) for handheld devices. It originates from a small software company, acquired by Google and is now owned by Open handset Alliance (OHA), where Google is a member. A description of Android is included and its advantages and disadvantages are discussed. Resources and recommendations on Android development and Android versioning are presented. Strategies on development are also suggested throughout this thesis. The development for an Android device and its data traffic characteristics is of interest, which is also included in this thesis. Connectivity and communication like connecting to Facebook and pulling data from an internet-connected web server, is discussed.