The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase I project is three-fold. First, accurate motion tracking is an open research problem, and the proposed approaches have the potential to significantly advance state-of-the-art in localization and tracking and facilitate new innovations. Second, there is the potential for significant commercial impacts. The project aims to introduce a disruptive technology in motion tracking to benefit a broad customer base. If successful, it can accelerate development of companies whose products benefit from motion tracking. Third, motion tracking has many applications and opens the door to new ways of interacting with everyday devices, education, and health care, which has profound societal impacts. This Small Business Innovation Research (SBIR) Phase I project proposes a cutting-edge novel motion tracking system based on audio signals. It promises to turn a mobile phone into a universal controller. By simply moving his or her hand holding a mobile phone, a user can play interactive games, interact with VR/AR headsets, and remotely control smart appliances. It offers four distinctive advantages: (i) high tracking accuracy, (ii) low-cost and easy deployment as it does not require any extra hardware and is a completely software-based solution, (iii) easy to use - simply by hand movement, and (iv) will work under a wide range of scenarios. The proposed technology can potentially revolutionize the gaming and VR/AR industries, and enable new applications in tele-presence, education, and health care.