 Study Design: We will employ sequential mixed qualitative and quantitative methods for intervention adaptation and testing. Specifically, we will dedicate year one of the award to creating and scripting the CBT mobile app intervention for anxiety, which will include multiple electronic features that enhance specificity to patients individual cancer-related concerns. Up to six patients with metastatic cancer will participate in an initial open pilot study to explore the usability and acceptability of the prototype application. Data from qualitative interviews with these participants will be used to refine and adapt the intervention further. In year two, we will enroll and randomly assign patients with anxiety and metastatic cancer to receive either the CBT mobile app intervention or an online health education program. Patients will self-administer the intervention protocol using a tablet. The target enrollment for the randomized-controlled trial is 120 patients CBT Mobile App N60; Control N60. Randomization will be stratified by study site and disease severity to demonstrate the generalizability of the intervention among patients with diverse malignancies in both academic and community cancer care settings. 