You can find the preprint of our manuscript with a full description of StudyU here:
Konigorski S, Wernicke S, Slosarek T, Zenner AM, Strelow N, Ruether FD, Henschel F, Manaswini M, Pottbäcker F, Edelman JA, Owoyele B, Danieletto M, Golden E, Zweig M, Nadkarni G, Böttinger E (2020). StudyU: a platform for designing and conducting innovative digital N-of-1 trials. arXiv:2012.14201. https://arxiv.org/abs/2012.14201.