Smartphone App-Based Mindfulness Intervention for French and English Speaker Cancer Survivors

Inclusion Criteria: * Adult ≥ 18 years * Diagnosed with any type of cancer (stages I-IV) * Completed primary treatment (i.e. surgery, chemotherapy, radiation therapy) at least 2 weeks (14days) prior. Note: ongoing maintenance therapy, hormone-blocking therapies, intermittent bone-modifying agents, herceptin and targeted therapy with trastuzumab are not exclusionary. * Have access to a smartphone with data or wifi connection. * Willing to devote 20-30 mins of time to mindfulness practices daily during the 4-week intervention period. * Participant consent must be appropriately obtained in accordance with applicable local and regulatory requirements. Each participant must sign a consent form (e-consent) prior to enrollment in the study to document their willingness to participate. * Participant is able (i.e. sufficiently fluent) and willing to complete the MBCS Journey and outcome measures in either English or French. The baseline assessment must be completed within required timelines, prior to randomization. * In accordance with CCTG policy, protocol intervention is intended to begin within 7 calendar days of patient randomization. * Participants must be willing to complete the MBCS Journey and complete the follow-up questionnaires Exclusion Criteria: * Major communication difficulties at the time of recruitment, as assessed by the research team (e.g. severe hearing impairment or cognitive impairment (score of ≤ 6; as assessed by the centre CRA using the three questions from the Brief Screen for Cognitive Impairment (BSCI)) listed in the screening CRF, which could interfere with completing the intervention and/or the questionnaires (i.e. inability to read or write) * Suffering from untreated Major Depressive Disorder or other psychiatric disorders that would interfere with participation. (Note: Participants will be referred for treatment and invited to call back once in remission). * Previous experience practicing in-person or app-based mindfulness once a week or more within the last year.