Feasibility and Acceptability of the Remote Oncology Symptom Assessment Application

The goal of this study is to determine whether a mobile application that combines real-time sensor data and patient-reported symptoms to trigger care-team contact recommendations is feasible and beneficial for patients receiving chemotherapy. The main questions it aims to answer are:

* Is the mobile application feasible and acceptable to patients? * Do the alerts and guidance improve symptom management, quality of life, and engagement with the care team during treatment?

Participants will:

* Complete a demographic questionnaire at the beginning of the study and quality-of-life and health questionnaires at the beginning, midpoint, and end of study. * Complete daily symptom ratings. * Wear a Fitbit activity tracker for 90 days. * At the end of the study, complete a semi-structured interview to provide feedback on the study. * Optional: At the beginning and end of the study, complete an in-person physical function assessment measuring balance (Short Physical Performance Battery).