Mobile usage grows very strongly in the recent years: we have more mobile users and more mobile data traffic which turns out the revolution of data collection. One common problem for the data collection is the expenses for collecting data from different data sources. One existing solution is outsourcing tasks in order to save personnel and travel expenses, which is called participatory sensing or community sensing. There are some more questions that are worth to be discussed in this book: What kind of data can we collect using mobile devices? Why do we use mobile devices to collect data? Is the accuracy good enough for research purposes? How do we store the data? In this book we will analyze the requirements of mobile data crowd sensing, come up with a data collection and storage solution by developing a mobile client prototype, and integrate it with an apposite service back end via Rest API.