A system for coupling accessory devices to a portable electronic device includes a casing that receives the portable electronic device. The casing has a front opening through which a display screen of a portable electronic device is accessible to a user, and a rear opening. The system further includes a plate element that is inserted into the casing and is positioned adjacent the rear opening such that a portion of the plate element is exposed by the rear opening. The system further includes an accessory device coupled to the plate element. The accessory device has an inner portion and an outer portion, such that when the accessory device is coupled to the plate element, at least part of the plate element is between the inner portion and the outer portion.