The Vira app is installed on the participant's phone. The app passively collects data from phone sensors (i.e., measures of physical activity, sleep patterns, mobility, and language patterns reflecting mood states and cognition) that are indicative of risk-relevant behavioral patterns and psychological states. It also so prompts users to answer a daily check in question. Mobile sensing data are processed to provide an automated assessment of the user's functioning. Users will be asked to use Vira for 12 weeks.

The Vira app can be used as a standalone product. After an initial 10-day period, during which the app assesses the relationship between the user's patterns of behavior and their day-to-day variations in mental health and wellbeing using passive mobile sensing, the user is able to access a personalized behavior change goal that is support by in app information and functionality.

The Vira app can also be supported by a health coach. The health coach interacts with the user (via an instant messaging platform) and who also schedules just-in-time reminders (i.e., "nudges") to arrive in the user's phone at scheduled times to support their behavior change plan. The Vira Health Coach Platform therefore integrates mobile sensing, self-report assessment, and just-in-time nudges and notifications into the coach's workflow.

The Vira app is installed on the participant's phone. The app passively collects data from phone sensors (i.e., measures of physical activity, sleep patterns, mobility, and language patterns reflecting mood states and cognition) that are indicative of risk-relevant behavioral patterns and psychological states. It also so prompts users to answer a daily check in question. Mobile sensing data are processed to provide an automated assessment of the user's functioning. Users will be asked to use Vira for 12 weeks.

Pre- to post-intervention changes in depressive symptoms will be assessed by the Patient Health Questionnaire (PHQ-8) an 8-item participant-report measure for screening for depression and for establishing depression severity. The total score ranges from 0-24, with a higher score indicating greater depression symptom severity.

To measure feasibility of implementation, the total number of active days using Vira during the study will be objectively collected via the Vira platform.

To measure feasibility of implementation, the total number of features used during the study will be objectively collected via the Vira platform.

Acceptability of the mobile app intervention and health coaching platform will be assessed using 11 items adapted from the Technology Acceptance Model. Scores range from 11 to 77, with higher scores indicating greater acceptability.