Information terminal device, information terminal management system, and storage medium in which program is stored

An information terminal device comprises a Widget management unit for managing the execution of Widget which is a single-function program that is displayed in a display unit of a display device. The Widget management unit comprises a policy determination unit for setting, in the Widget, an operation policy including operation restriction and priority regarding the display state in the display device, and a reliability degree determination unit for determining the degree of reliability of the Widget, and when the state of movement gets into a preset state, the Widget management unit restricts the operation of the Widget according to the operation policy and the degree of reliability and preferentially displays positional information and information relating to a guidance state.