Primary outcome measures.
RECRUITMENT
Primary outcomes were based on guidelines for evaluating novel health interventions, including conducting pilot trials [Feasibility: recruitment, intervention uptake, and retention at Acceptability: intervention adherence (including the average number and length of tool sessions completed, and the proportion of participants completing an average of three tools per week, or 12 in total), participant satisfaction, and reasons for nonadherence.Engagement: average number of tool sessions completed, average total duration of tool usage, self-reported conditions that prompt tool usage, self-reported pattern of tool usage, and one question adapted from section B of the Mobile App Rating Scale (MARS [Transferability: One item adapted from section E of the MARS.Relevance: One item assessing subjective self-reported of the interventions.Lasting negative effects: One item adapted from recent guidelines on assessing negative effects [