Device holder assemblies include a first device panel and a second device panel that are configured to selectively couple a first and a second portable computing device to the device holder assembly. The device holder assemblies generally include a spine that is hingedly connected to the first device panel and the second device panel, such that the device holder assembly is repositionable between an open position and a closed position by rotating the first device panel and the second device panel about the spine. The spine may also include a computing entity including driver software that allows the first and second portable computing devices to be operated in conjunction with one another when selectively coupled to the device holder assembly.