Context of īnteraction
User a	Patients: The target population was patients with specific illnesses or diseases.
	Healthcare providers: The target population was healthcare providers.
	Any user: The target population was the general public including caregivers or healthy individuals.
	Undetermined: The target population of the app was not able to be determined.
Health domain areas a	Mental health: The app was developed for a mental health domain area.
	Primary care: The app was developed for a primary care domain area, which included healthbots containing symptom assessment, primary prevention, and other health-promoting measures.
	Other: The app was developed for one of the following focus areas: Anesthesiology, Cancer, Cardiology, Dermatology, Endocrinology, Genetics, Medical Claims, Neurology, Nutrition, Pathology, Sexual Health
	Undetermined: The domain area of the app was not able to be determined.
Theoretical or therapeutic underpinning	Yes: The app included a theoretical or therapeutic underpinning (ex. Cognitive Behavioral Therapy (CBT), Dialectic Behavioral Therapy (DBT), Stages of Change/Transtheoretical Model).
	No: The app did not include a theoretical or therapeutic underpinning.
	Undetermined: The theoretical or therapeutic underpinning of the app was not able to be determined.
Level of personalization b
Automation	Yes: The app used personalization.
	Implicit: Information needed for personalization was obtained automatically through analysis of user interactions with the system.
	Explicit: Information needed for user models required users’ active participation.
	No: The app did not use personalization.
	Undetermined: The personalization of the app was not able to be determined.
Target	Individuated: The personalization was targeted at a specific individual.
	Categorical: The personalization was targeted at a group of people.
Aspects of system	Content: The information itself could be personalized.
	User interface: The way in which the information is presented could be personalized.
	Delivery channel: The media through which information is delivered could be personalized.
	Functionality: The functions of the app could be personalized.
Additional engagement features	Appointment schedulingc: The app included an appointment scheduling feature.
	Clinic/Services locatorc: The app included a clinic/service locating feature.
	Create account: The app included an option to create an account for the app in order to store information for later use.
	Decision aid supportc: The app included a decision aid support feature that advised users to seek additional medical care if appropriate.
	Embodied conversational agent/chatbotd: The app included an embodied conversational agent/chatbot.
	Integration of videosc: The healthbot integrated videos into its conversations.
	Main menu/navigation barc: The app included a main menu/navigation bar.
	Push notifications/reminders to usec: The app included push notifications/reminders to use it.
	Required purchase to use: The app required purchase to use or offered in-app purchases.
	Redirect to doctor/therapist: The app redirected users to a doctor or a therapist.
	No additional features: The app did not include additional features.
	Undetermined: The app’s additional features were not able to be determined
	Othere: The app included one or more of the following features (see footnote)
Mobile/web access f	Mobile: The app was available as an installable software via mobile devices and tablets.
	Web: The app was accessible via a web browser on laptops, desk computers, phones, tablets, etc.
	Undetermined: The app was not accessible.
Security	E-mail verification: The app sent a one-time password to the user’s e-mail for identity verification.
	Text verification: The app sent a one-time password to the user’s phone number for identity verification.
	Social media verification: The app provided the option to sign into a social media account for identity verification.
	Passcode to access app: A password was required to access the app.
	No security elements: The app did not contain any security elements.
	Undetermined: The security of the app was not able to be assessed.
Privacy	HIPAA: The app stated that it was HIPAA compliant.
	Child Online Privacy and Protection Act (COPPA): The app stated that it was COPPA compliant.
	Medical disclaimer: The app provided a medical disclaimer that it is not a substitute for care from a healthcare professional.
	Other privacy elements: The app contained one of the following privacy elements: encrypted data disclaimer, app-specific privacy policy
	No privacy elements: The app did not contain any privacy elements.
	Undetermined: The privacy of the app was not able to be assessed.

^a(adapted from Montenegro et al.).

^b(adapted from Kocaballi et al.).

^c(adapted from Chen et al.).

^d(adapted from ter Stal et al.).

^eOther: Billing; Bluetooth Connection to Health Device; Clarity of text/images (Chen); Connect to store; Emergency Mode for Urgent Matters; Forum or Social Network (Chen); Gamification (Chen); GPS (Chen); Internal search function (Chen); Lab Results/Health History; Link to additional information; Order Tests/Medication; Tracker for food or symptoms.

^f (adapted from Laranjo et al.).