This book is intended for scientists and graduate students who need to understand and execute Internet of Things (IoT) based applications-a research area which is increasingly become important worldwide. This book includes five chapters which incorporate the study of IoT and implementation of particular application. Each chapter is elaborated with implementation of a particular application which includes hardware and software description to easily understand and implement it.Every effort was made to incorporate minuscule details for the application-centric hardware and software. This book covers description and implementation of IoT based applications for Smoke and methane detection in Coal mines, IoT for UAV based pollution measurement, IoT based Thermoelectric Power Generation, Fingerprint based Security System, and Fingerprint Module based Door Unlocking System.