Inclusion Criteria:  age 16-20 vaped nicotine on ≥20 days out of the last 30 elevated depressive symptoms, defined as a score of ≥10 on Patient Health Questionnaire-8 (PHQ-8) during preliminary screening and the Adolescent Patient Health Questionnaire-9 (PHQ-9A) at final eligibility currently own an iOS or Android smartphone report willingness to utilize an app for quitting vaping nicotine (response of "yes" on yes/no item) have a valid e-mail address that is checked regularly or regular access to text messages (for follow-up assessments) ability to read the consent form has been seen (in person or remotely) by a primary care physician within the last year  Exclusion Criteria:  smoked cigarettes or used other tobacco products on ≥9 days out of the last 30 severe visual impairment currently receiving treatment for vaping or tobacco use current suicidal ideation, defined as a response ≥1 on item nine of the PHQ-9A or ≥2 on item 9 of the BDI-II household member currently enrolled in the study inability to read the consent form