A modular electronic device system includes an electronic device and a cover for the device that allows the device to be mechanically and electrically mounted to a stand or device adapter on the rear side of the cover. The cover or device adapter can be connectable to modularly attachable and removable accessory devices and can provide electrical ports for powering and operating the accessory devices. While mounted to a stand, power and data communications can be provided to the electronic device, cover, and accessory devices from the stand or an external source. The modular components of the system can be interchangeable to allow the system to be adapted to many different settings and use cases based on the types of components included as the accessory devices and based on the number of accessory devices used.