Move Together Boston Feasibility Pilot (Sit Less, Move More App for Black Breast Cancer Survivors & At-Risk Relatives)

Inclusion Criteria: * 1a) Key informants (for interviews) * Members of the community/advisory groups, community health centers, or faith-based network members (e.g., Pink and Black, Faces of Faith). * English speaking adults. * (1b) Breast cancer survivors and relatives (for interviews) * Self-identify as Black or African American * Age 18 and over * English speaking * Female breast cancer survivor status post curative antineoplastic treatment (except ongoing hormonal treatment) with no evidence of disease, OR a first degree blood relative (parent, child, or full sibling), of any gender, of a so defined breast cancer survivor * Self-report ever using a smart phone * (2) Breast cancer survivors and relatives (for user testing/interviews) * Self-identify as Black or African American * Age 18 and over * English speaking * Female breast cancer survivor status post curative antineoplastic treatment (except ongoing hormonal treatment) with no evidence of disease, OR a first degree blood relative (parent, child, or full sibling), of any gender, of a so defined breast cancer survivor * Self-report willing/able to download the app for testing on a smart phone * Self-report willing/able to meet via Zoom for interview * (3) Breast cancer survivors and relatives/"buddies" (for pilot testing) * Self-identify as Black or African American * Age 18 and over * English speaking * Breast cancer survivor status post curative antineoplastic treatment (except ongoing hormonal treatment) with no evidence of disease, OR a blood relative, of any gender, of a so defined breast cancer survivor * Self-report willing/able to participate with a blood relative in survivor relative dyad * Self-report willing/able to download the app for use on a smart phone * Self-report willing/able to meet via Zoom for instructions and interview Exclusion Criteria: * (1a) Key informants (for interviews) --None * (1b) Breast cancer survivors and relatives (for interviews) * Requires medically supervised physical activity (Physical Activity Readiness Question for Everyone, PAR-Q+, Question 7) * Pregnant women * (2) Breast cancer survivors and relatives (for user testing/interviews) * Requires medically supervised physical activity (Physical Activity Readiness Question for Everyone, PAR-Q+, Question 7) * Pregnant women * (3) Breast cancer survivors and relatives/"buddies" (for pilot testing) * Meets exclusion criterion of the Modified Physical Activity Readiness Questionnaire (PAR-Q) (modified) * Participated in interviews or user testing in prior phases of the study