Emerging evidence suggests that smartphone applications could support smokers in quitting. This study employed a single-group cohort design to assess both the practicality and user acceptance of a novel mobile app developed for smoking cessation in China, while also examining its effect on smoking quit rates. This study recruited 180 smokers from two mainland Chinese cities who were willing to attempt quitting. Participants engaged with a cognitive behavioral therapy (CBT)-based smoking cessation app over a 37- to 44-day period, which included a 7- to 14-day preparatory phase before quitting and a 33-day post-quit intervention. Measures of program feasibility, user acceptability, and smoking outcomes were collected at three stages: at the time of app installation, during the pre-quit phase, and at multiple points after quitting (days 7, 15, and 33). Out of 180 participants, 163 (90.6%) completed the study. Daily engagement with the app was high, with 76–89% of participants logging in at least once per day throughout the baseline, pre-quit, and post-quit stages (days 7, 15, and 33). Overall satisfaction remained strong, reaching approximately 90% at each stage and showing a significant increase from 93% at baseline to 98% at day 33 post-quit (p = 0.021). Confidence in the app’s ability to support smoking cessation also rose substantially, from 69% initially to 97% at day 33 (p < 0.001). Participants expressed high satisfaction (80–90%) with most features, particularly the informational content. Intention-to-treat analyses indicated that 63.9% maintained continuous abstinence for 33 days, while 7-day point prevalence abstinence rates were 81.7%, 87.2%, and 77.8% on days 7, 15, and 33, respectively. The findings indicate that the smartphone-based intervention for smoking cessation is both feasible and well-accepted, offering a novel digital treatment approach that could help overcome the limitations of traditional in-person cessation programs and expand access to smoking cessation services across China.
