The International Journal of Ubiquitous Computing (IJU) is a quarterly peer-reviewed journal that provides a forum for sharing knowledge and research in ubiquitous computing theory, methodology and applications. Ubiquitous computing requires robust and reliable systems for end users. The journal aims to provide a platform for researchers and practitioners to share developments in areas like context awareness, distributed systems, human-computer interaction, security and more. Authors are invited to submit papers by October 2nd, 2021 for potential publication.