BackgroundPatients with multiple myeloma (MM) increasingly face complicated treatment regimens. E-health may support patients and healthcare providers in enhancing a patient-centered healthcare approach. Therefore, we aimed to develop a patient-centered multi-modality e-health application, to assess the application for usability and end-user experiences.MethodsThe application was developed following an iterative “action-based” methodology using the design thinking approach. Key end users participated, and relevant stakeholders were consulted in the development process. First, the care pathway was evaluated, the focus of development was determined, and a solution ideated during recurring multidisciplinary meetings. Second, a prototype was tested and improved. Third, a subsequent prototype was evaluated during a pilot study with patients and healthcare professionals on usability, usage, and experiences.ResultsThe multi-modality application, named the “MM E-coach,” consisted of a newly developed medication module, patient-reported outcome (PRO) questionnaire assessments, a messaging service, alerts, information provision, and a personal care plan. The median system usability score was 60 on a scale of 0–100. Patients appreciated the medication overview, healthcare professionals appreciated the outpatient clinic preparation module, and both appreciated the messaging service. Additional recommendations for improvement mostly revolved around the flexibility of functionalities and look and feel of the application.ConclusionsThe MM E-coach has the potential to provide patient-centered care by supporting patients and caregivers during MM treatment and is a promising application to be implemented in the MM care pathway. A randomized clinical trial was initiated to study its clinical effectiveness.Supplementary InformationThe online version contains supplementary material available at 10.1186/s40814-023-01307-0.