1. A portable therapy device comprising: a camera configured to generate images of a user; a therapy application database configured to store therapy applications; a processor configured to: select, from the therapy application database, a therapy application appropriate for assisting in physical or cognitive rehabilitation or therapy of the user, invoke the therapy application, recognize a gesture of the user from the generated images, and control the invoked therapy application based on the recognized gesture; and a display configured to display an output of the controlled therapy application; wherein the processor is configured to select the therapy application by: recognizing, from one of the images, whether the user possesses a controller; and selecting a therapy application that does not require possession of the controller, if the user is recognized to not possess the controller.