This study is focused on the development and pilot/feasibility testing of a smartphone application to promote a healthy diet, increase physical activity, and prevent weight gain in adolescent survivors of childhood cancer.

While successful advancements in treatment for childhood Acute Lymphoblastic Leukemia (ALL) have resulted in a growing cohort of survivors, these survivors are at risk for a number of long-term health problems. This study proposes to develop and conduct feasibility testing for a smartphone application that would deliver a health behavior intervention to this population.

A formative phase focused on intervention and software development will be followed by a pilot/feasibility test of the intervention. Participants in the intervention will receive a customized study-designed mobile phone app with a social networking component in which users will be able to support one another. They will also receive personal support from a health counselor to help set goals and discuss areas of concern.

Inclusion Criteria:

• Participants must speak & read/write fluent English;
• Adolescent must be between 12 and 19 years of age;
• Adolescent must have a previous diagnosis of childhood Acute Lymphoblastic Leukemia;
• Adolescent must be "off-therapy" (i.e., not in active or maintenance phase of cancer therapy) for at least 2 years;
• Adolescent must be cleared by his/her physician to participate (defined by obtaining a score of 80 or greater on the Karnofsky Scale as determined by their physician);
• Participants must have a working phone number;
• Adolescents must live at home with parents in order to facilitate parent involvement via support materials.

Exclusion Criteria:

• Physician reports that the patient has deficits in neurocognitive functioning that would preclude him/her from participating in a cognitive-oriented intervention;