Table 3. Summary of key themes and insights from qualitative results.

Theme	Subthemes or key insights	Supporting quotes
Motivation and readiness to quit	App more useful for those highly motivated or ready to quit Lower readiness linked to lower engagement	“I was pretty motivated... that gave me a definitive start date.” [ID 27] “I’m not there yet... the app helped …but I think you have to be a 100% ready.” [ID 01]
Barriers to quitting smoking	Stress, mental health, daily hardships Habitual use and nicotine addiction Social contexts and emotional triggers	“The more stressed I am, the more I smoke...” [ID 19] “It’s really hard to quit... the brain always makes excuses to get it” [ID 28]
Helpful app features	Cigarette tracking increased awareness Trigger identification and coping strategies Resource library, visual feedback (savings, graphs, progress) Gender-specific content resonated with users	“...just reminding me to get outside and…do something other than just …smoking...” [ID 11] “Everything they were talking about (in the videos) is how I felt...” [ID 18]
Features in need of improvement	Burden of frequent tracking/logging Usability issues (eg, journal entries, notifications) Desire for more interactivity and real-life testimonials	“It just seemed like the app wanted me to go into it every time...” [ID 07] “I would like to get more like a free open option to write stuff down” [ID 19]
Desire for additional support	Suggestions for live support or artificial intelligence–based chat features App more effective when paired with counseling or pharmacotherapy	“A live connection... someone like ...a sponsor.” [ID 14] “Maybe they should be starting that (medication) already before they use the app, so they already have a jump start, so to speak” [ID 29]