The poorer cancer outcomes experienced by Indigenous Australians result from reduced access to culturally appropriate support services. Living with cancer is linked to a high prevalence of social isolation, stress, anxiety, and consequently experiencing lower level of psychosocial well-being. Resources to support the psychosocial well-being of Indigenous people with cancer must be available at the point of need. The web is increasingly becoming a viable platform for delivery of health services that are accessible at any time and from anywhere. There is a lack of culturally and language-appropriate web-based health services for Indigenous Australians with cancer and this paper which is a part of a bigger study informs the development of a culturally and language-appropriate smartphone-based support intervention for improving the psychological well-being of Indigenous Australian people with cancer. Drawing on evidence from research across diverse fields and applying a multi-theory perspective, we developed a conceptual framework that depicts the features needed for a smartphone based health intervention to effectively support Indigenous Australians living with cancer and enable them to obtain culturally appropriate cancer care support and experience better psychosocial well-being. Next, we conducted structured interviews with experts to examine the sense making and validity of the proposed framework.