The goal of this observational study is to assess the satisfaction and usability of an interactive and patient-centered mobile application (app), Oleena™, designed to assist head and neck cancer patients undergoing chemoradiation in managing common and distressing symptoms in real-time, as well as to assess the satisfaction and usability of the related HCP web portal. Additional secondary usage and clinical endpoints that would be used to assess intervention efficacy in future trials will be collected.

Inclusion Criteria:

• ≥18 years old
• Planned to initiate chemoradiation for locally advanced head and neck cancer at Moffitt Cancer Center
• ECOG performance status ≤2
• Able to speak and read US English or Spanish
• Able to provide informed consent
• Owns a smartphone with an iOS or Android operating systemcompatible with Oleena
• Able to access the internet
• Willing to use a mobile app for symptom management

Exclusion Criteria:

• Documented or observable psychiatric or neurological disorders that would interfere with study participation (e.g., psychosis, active substance abuse).
• A prior cancer diagnosis except for non-melanoma skin cancer.
• Currently enrolled in an industry-sponsored clinical trial.
• Pregnant women.
• Patients undergoing RE-irradiation
• Patients who meet the inclusion criteria may be excluded at Investigator's discretion

Patients with locally advanced head and neck cancer initiating chemoradiation. Patients will use Oleena for 90 days from the initiation of the treatment and be instructed to enter symptoms as they occur and receive self-management recommendations via the app. Surveys will be completed by patients at baseline, 30, and 90 days after initiation. A subgroup of patients (20) will be asked to participate in exit interviews with a study team member regarding their experience with the app.