A Culturally-Tailored Mobile Health and Social Media Physical Activity Intervention for Improving Physical Activity in Hispanic or Latino/Latina Adolescent and Young Adult Childhood Cancer Survivors, Walking Juntos Study

Inclusion Criteria:

* Patient must be ≥ 15 years and \< 21 years at the time of enrollment
* First diagnosis of malignant neoplasm (International Classification of Diseases for Oncology \[ICD-O\] behavior code of "3") in first and continuous remission at the time of enrollment
* Curative cancer treatment must have included chemotherapy (including cellular therapy) and/or radiation (including radioactive iodine). Note: Certain stem cell transplant procedures are excluded. Reminder: Children's Oncology Group (COG) therapeutic trial participation is not required
* Completed all chemotherapy and/or radiation therapy in the last 3-36 months. This includes completion of all oral (e.g., tyrosine kinase inhibitors) and/or maintenance chemotherapy
* Self-report of \< 420 minutes of moderate-to-vigorous physical activity per week as assessed and documented via the study-specific Physical Activity Worksheet. Note: See the case report forms packet on the COG study web page for the study specific Physical Activity Worksheet
* Ambulatory and no known medical contraindications to increasing physical activity
* No known significant physical or cognitive impairment that would prevent use of the electronic devices used for the protocol intervention (e.g., Fitbit, smartphone, tablet, or computer)
* Able to read and write Spanish or English
* Self-identify as Hispanic, Latino/Latina/Latinx

Exclusion Criteria:

* Patients with previous allogeneic hematopoietic stem cell transplant (HSCT) are excluded. Note: Patients with previous autologous HSCT, chimeric antigen receptor T-cell (CAR T-cell) therapy, and other cellular cancer therapies can participate as long as all other eligibility criteria are satisfied
* Post-menarchal female patients who are pregnant or planning to become pregnant in the next year are excluded. Note: Pregnancy status can be established by clinical history with patient. Post-menarchal female patients are eligible as long as they agree to use an effective contraceptive method (including abstinence) during study participation
* Participants who were enrolled in ALTE2031 (Step by Step) cannot enroll in ALTE2321. Participants who were enrolled in ALTE2321 stage 1 (cultural tailoring) cannot enroll to participate in stage 2 (RCT)
* All patients and/or their parents or legal guardians must sign a written informed consent. Note: Informed consent may be obtained electronically/online if allowed by local site policy and institutional review board (IRB)/research ethics board (REB) of record
* All institutional, Food and Drug Administration (FDA), and National Cancer Institute (NCI) requirements for human studies must be met