The invention relates to new uses of smartphones (1, 1') and comparable mobile digital terminal devices. This comprises uses of a digital terminal device, preferably in the form of a mobile device such as a smartphone or the like, wherein special application software (an app) is stored and run on the terminal device and wherein the terminal device (1) is advantageously used together with a holding device (2) arranged or to be arranged on the head of a user (5), particularly in accordance with EP 2 103 862 or EP 2 562 462 or US 2012/0175394 or DE 20 2009 009 326 or DE 24 20 2013 000 740, so that the hands (6) of the user (5) are free and thus additional application possibilities arise during the use of the terminal device (1), for example by using an external controller. Said additional application possibilities relate
inter alia to e-book readers of a new type, social games and toys, virtual configurators, for purchasing a motor vehicle for example, a double camera usage in smartphones, music stands of a new type for learning musical instruments and new possibilities for remotely controlling electronic objects such as toys or the like.