This app is the “Bone” version in the Tumorpedia series, a collection of apps that serve as an encyclopedia of orthopaedic oncology based on www.bonetumor.org. This version includes over 70 orthopaedic bone tumors. Each topic is divided into general information, incidence and demographics, xrays, MRI, CT, pathology, differential diagnosis, and treatment. The amount of information presented for each topic is variable, but generally a specific and informative overview of the topic is included. The images are especially useful for demonstrating “typical” appearances on imaging exams and pathologic specimens. The app also includes an “updated” feature, suggesting that the database may undergo regular updates in the future. It appears that images are downloaded in real-time from a server, thus the app is of limited use when no WiFi or wireless data signal is available. As a result, some of the images did not load during my testing. Overall, this series of orthopaedic tumor information is an inexpensive and useful reference for orthopaedic trainees, nurses, and other medical providers who diagnose and treat musculoskeletal tumors. Because this is a first version, hopefully future versions will be available with improved functionality.