This clinical trial compares two smartphone applications, called Actify! (A & B) for improving smoking cessation outcomes in individuals who smoke. Actify! A is an app grounded in behavioral activation therapy, an evidence-based treatment for depression that can also be used to modify health behaviors such as smoking. The Actify! B app provides evidence-based tobacco cessation strategies based on current clinical guidelines.

OUTLINE: Participants are randomized to 1 of 2 arms.

ARM I: Participants use the Actify! A app, which helps users identify personal values and meaningful activities, prompts users to schedule and complete meaningful activities, visualizes progress towards meeting activity and smoking-related goals, and provides tailored messages, resources, daily tips, personalized feedback, inspirational messages, and user stories, for 8 weeks on study.

ARM II: Participants use the Actify! B app, which contains quit advice, tools for tracking smokefree days, progress and cravings, guidance on preparing to quit, managing cravings and withdrawal, recovering from slips, and a mood management feature, for 8 weeks on study.

After completion of study intervention, participants are followed up at 6 months.

Inclusion Criteria:

• Age 18 or older
• Currently smoke, averaging at least 5 cigarettes/day for the last 30 days
• Interested in quitting smoking in the next 30 days
• Experience downloading and using one or more apps on their smartphone
• Either screens negative for depression (Patient Health Questionnaire - 9 item [PHQ-9] score 0-4; n = 906) or screens positive for mild to moderately severe current depressive symptoms (PHQ-9 score 5-19; n = 906)
• Willing and able to complete all study activities and to receive compensation by mail
• Comfortable reading and writing in English
• Have a mobile data plan and/or access to WiFi to support the use of the assigned app
• Reside in the United States (US)
• Willing to provide information for an emergency contact in case of serious concerns about the participant's physical or mental health

Exclusion Criteria:

• Self-report of currently receiving behavioral treatment for depression (e.g., psychotherapy or counseling, web- or app-based interventions); current use of pharmacotherapy for depression or for other mental health conditions that are not otherwise excluded is allowable (e.g., benzodiazepines, anticonvulsants, opioid agonists, antipsychotics)
• Severe depression (PHQ-9 ≥ 20)
• Current suicidal ideation reported on the PHQ-9
• History of a suicide attempt
• Self-reported lifetime diagnosis of bipolar disorder, schizophrenia, schizoaffective disorder, antisocial personality disorder, or borderline personality disorder; or self-reported lifetime diagnosis of an alcohol or drug use disorder with use of the substance(s) in the past 30 days
• Currently receiving other smoking cessation treatments, including pharmacotherapies (nicotine replacement therapy, bupropion, or varenicline) and behavioral interventions (e.g. quitline counseling, other digital health programs), but excluding electronic (e)-cigarettes/vaping
• Previous use of the QuitGuide program
• Employees/family of investigator or study center
• Member of the same household as another participant
• Woman who is pregnant or breastfeeding, or planning to become pregnant
• Having a Google voice number as their primary phone number (due to association with fraudulent study entry attempts in our previous work)
• Currently incarcerated
• Participated in earlier studies to develop the Actify! app

The study researchers for this study plan to preserve and share the following:

• Survey Data: De-identified individual and aggregate survey data (including raw and recoded data) necessary to replicate main outcomes will be shared. The de-identification process will remove direct and indirect respondent identifiers prior to sharing.
• App utilization data: Individual level, de-identified aggregate data necessary to replicate main outcomes (e.g., summary number of log-ins, pages viewed, or other app events) will be shared. The de-identification process will remove direct and indirect respondent identifiers.

Documentation made publicly available to the research community will include PDFs of various study materials.

At this time, the study researchers plan to share scientific data and meta-data in NCI's Cancer Data Service (CDS): https://dataservice.datacommons.cancer.gov/#/home.

Final data submission and release of data used in publications will occur at the time of publication. Other shared data will be made available at or before the end of the project period. The study researchers will follow the data retention plan of the final selected repository, but at a minimum, researchers intend to ensure that data is available for a period of not less than 5 years after the end of this trial.

All data sharing will be done in compliance with NIH data sharing policies, applicable laws and regulations, and in accordance with guidance from journal publishers. CDS allows open and controlled access to data to ensure access is provided to qualified researchers, data access is tracked, and users understand how to cite and credit use of the data. Data will only be shared for non-profit, non-commercial and non-proprietary purposes to qualified researchers or as allowed by CDS. Based on the nature of the data, which is not sensitive, the study researchers anticipate making it publicly available (as opposed to controlled access) but will follow final recommendations from the IRB as to whether access should be controlled.