Blockchains are seen as a technology for the future, which reduce the cost of trust and revolutionize transactions between individuals, companies and governments. The sense of using blockchains is to minimize the probability of errors, successful frauds and paper-intensive processes. For these reasons, blockchains already have and will have a significant impact to the society and every day's life, especially in field of Machine to Machine (M2M) communications, which are one of the basic technologies for Internet of Things (IoT). Therefore, blockchains with their inherent property to provide security, privacy and decentralized operation are engine for todays and future reliable, autonomous and trusted IoT platforms. Specially, a disruptive role of ledger technologies in future smart personal mobility systems, which combine smart car industry, smart energy/smart cities will be explained in the book, considering its importance for development of new industrial and business models.