[This corrects the article DOI: 10.2196/24365.].
©Ran Bai, Le Xiao, Yu Guo, Xuequan Zhu, Nanxi Li, Yashen Wang, Qinqin Chen, Lei Feng, Yinghua Wang, Xiangyi Yu, Chunxue Wang, Yongdong Hu, Zhandong Liu, Haiyong Xie, Gang Wang. Originally published in JMIR mHealth and uHealth (https://mhealth.jmir.org), 17.06.2021.