Publisher's note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

BackgroundNausea is a common and distressing side effect for children in chemotherapy. Antiemetic recommendations are based on limited literature and prospective evaluation of antiemetic efficacy is required. Smartphone applications (apps) may collect patient-reported outcomes with precision and effectiveness1. We developed a smartphone app to track nausea in pediatric cancer patients during chemotherapy.MethodsMedical researchers, pediatric oncologists and software engineers worked synergistically in the development. We translated the validated Pediatric Nausea Assessment Tool to score nausea severity2. We conducted three rounds of patient-feedback and modification.ResultsThe app has a definition module where the child centers the attention to the concept of nausea. The child can then express nausea severity with four faces and the child’s own definition of nausea is incorporated in the question2. The app includes a notification system to ensure high response rates. All participants felt that the app was user-friendly, intuitive and that time spent was acceptable.ConclusionThe app is a user-friendly tool to assess nausea in pediatric cancer patients that can ease future pediatric antiemetic trials.ReferencesStone AA, Shiffman S, Schwartz JE, et al. Patient compliance with paper and electronic diaries. Control Clin Trials 2003 Apr;24(2):182–99.Dupuis LL, Taddio A, Kerr EN, et al. Development and validation of the pediatric nausea assessment tool for use in children receiving antineoplastic agents. Pharmacotherapy 2006;26:1221–31.Disclosure(s)Nothing to disclose