Table 3.

Summary of key themes extracted from students’ open-ended responses.

Theme				Example
Motivations for downloading and using health apps
	A desire for knowledge
		Desire to better understand menstrual cycle (female respondents)	“My doctors told me to track my period and I kept forgetting to write it on paper, but I saw a you-tuber use an app to track their period and decided to give it a go.” (Female, aged 12 years)
		Desire to better understand one’s own health, health behaviors, and mental health, often to help change behaviors	“MyFitnessPal provides every aspect from eating and weight health to physical health. I also needed an app which provided all of it so I had one place to store my health and progress.” (Male, aged 13 years) “What motivated me to download this app and then use it was that I wanted to keep a record of my health level, and later to see if the level increased or decreased and why. This also motivated me to increase my health level and be involved with more sporting activities.” (Female, aged 12 years)
	Desire to improve health and health behaviors
		Wanting to improve fitness, lose weight, get healthy, and improve sleep	“Wanted to get more fit.” (Female, aged 12 years) “Because I am very unactive and unfit.” (Female, aged 12 years)
	Other motivations		To be more organized (eg, with health appointments) They only downloaded the app to assist a wearable device to function (eg, Fitbit app) Others had recommended they download the app and use it The app came preinstalled on their phone
Useful features of favorite health apps
	Tracking
		Tracking a wide range of health issues and behaviors perceived to be an attractive feature of health apps (eg, tracking steps; sleep; exercise sessions; the distance and speed of runs and walks; menstrual cycles; and food intake, including detailed calorie counting and mood)	“It counts my exercise, my activity and my steps.” (Male, aged 14 years) “You can enter what you eat in a day and it will tell you if you need to stop eating something or eat something.” (Female, aged 13 years) “Allows me to track my feelings and health.” (Female, aged 14 years)
	Providing guidance
		Most useful features of health apps described to be features that provided guidance on health issues and behaviors (eg, guidance on workout routines; healthy foods, including recipes and scanning food items; and how to improve mood)	“The healthy recipes and the way I can scan food items to find out if they are healthy or not.” (Female, aged 13 years) “The recommended workouts for my age.” (Male, aged 12 years) “It has designed workouts that you can do and it shows you how to do them.” (Female, aged 13 years)
	Other useful features		Entertainment Goal setting Reminders to perform healthy behaviors Allowing communication or competition with friends