RecruitingBehavioural interventionIntegrating Pain-CBT Into an mHealth Analgesic Support Intervention for Patients With Chronic Pain From Advanced CancersSmartphone Technology to Alleviate Malignant Pain (STAMP) + Cognitive Behavioral Therapy for Pain (STAMP+CBT) The purpose of the study is to develop and refine the mHealth pain-CBT app intervention and carry out a randomized pilot to test the novel mHealth (Mobile health technology) intervention, which harmonizes psychological and pharmacological support for advanced cancer pain. The name of the study smartphone application involved in this study is: -STAMP+CBT