Software design and development; Software development in the field of blockchain and distributed ledger technology (DLT); Software development in the framework of software publishing; Software engineering services; Authentication of data in the field of online software applications using blockchain technology; Computer software design; Computer software development; Custom design of computer software; Design and development of software in the field of mobile applications; Design and development of on-line computer software systems; Design, development and implementation of software; Providing temporary use of on-line non-downloadable software for accessing, reading, and tracking information in the field of online software applications on a blockchain; Providing user authentication services using blockchain-based software technology for cryptocurrency transactions; Research and development of computer software; Smartphone software design; User authentication services using blockchain technology for online software applications