Men who have sex with men (MSM) in China have a high risk for HIV infection but experience suboptimal rates of HIV testing and service engagement due to various social and structural barriers. We developed a mobile health (mHealth) intervention entitled "WeTest-Plus" (WeTest+) as a user-centered "one-stop service" approach for delivering access to comprehensive information about HIV risk, HIV self-testing, behavioral and biomedical prevention, confirmatory testing, treatment, and care. The goal of the current study was to investigate the feasibility of WeTest+ to provide continuous HIV services to high-risk MSM. Participants completed a 3-week pilot test of WeTest+ to examine acceptability, feasibility, and recommendations for improvement. Participants completed a structured online questionnaire and qualitative exit interviews facilitated by project staff. "Click-through" rates were assessed to examine engagement with online content. 28 participants were included, and the average age was 27.6 years (standard deviation = 6.8). Almost all participants (96.4%) remained engaged with the WeTest+ program over a 3-week observational period. The majority (92.9%) self-administered the HIV self-test and submitted their test results through the online platform. Overall click-through rates were high (average 67.9%). Participants provided favorable comments about the quality and relevance of the WeTest+ information content, the engaging style of information presentation, and the user-centered features. This pilot assessment of WeTest+ supports the promise of this program for promoting HIV self-testing and linkage to in-person services for MSM in China. Findings underscore the utility of a user-centered approach to mHealth program design.