The intervention is a supportive information and self-management tool housed on the SeamlessMD mobile app, created in collaboration with the SeamlessMD development program and informed by foundational research. The application will be used as an information hub and self-management/navigation tool alongside usual care, to address the physical, psychosocial, and practical needs of breast and colorectal cancer survivors. Note that the intervention will not seek to change or impact a survivor's follow-up care plan, as decided upon by the participant and their care team.

Case report forms will be used to track recruitment metrics. The following demographics will be collected to monitor the diversity of those participating: cancer type (breast, colorectal), stage at diagnosis (in situ, stage 1, stage 2, stage 3, do not know), age (in years, prefer not to say), sex assigned at birth (male, female, intersex, prefer not to say), gender (man, woman, non-binary, other, prefer not to say), residence (rural, suburban, urban, prefer not to say), and highest level of education achieved (less than high school, high school, some post-secondary (college or university), diploma or degree, prefer not to say).

Case report forms will be used to track retention metrics.

Usage metrics will be collected using the SeamlessMD software to determine the following: 1) how often the intervention was accessed by participants, 2) what elements of the intervention were accessed most, and 3) what elements of the program were utilized the least.

Assessed via one-on-one semi-structured interviews with a sub-sample of study participants and providers at both study sites. Semi-structured interviews were chosen over focus groups for this component because the research team is seeking individual experiences with the intervention. Interviews will be carried out by a member of the research team on video conferencing software using a predetermined interview guide and will take approximately 45 minutes. The questions will center around the study participant's follow-up care experience while being supported by the intervention. Interviews with providers will focus on the feasibility and acceptability of the supportive self-management tool.

Will be assessed using the 6-item Cancer Worry Scale, a validated patient-reported instrument. Cancer Worry Scale (CWS) scores range from 6 to 24 points. A score of 6 points indicates low worry, while a score of 24 points indicates very high worry.