This invention provides a mechanism for restricting invocation of wireless mobile terminal (Smartphone) apps whose execution creates a vehicular driving hazard. Events that cause such hazards are included. An event example is “being a vehicle's driver” and attempting to do the app of texting. Events to restrict an app invocation are also included. These include remote restrictions, such as parents remotely turning off the texting app of their children driving an automobile. Spatial parameters, such as driving on high speed and/or heavy traffic roads, also represent restricting events. Events are inserted within an Invoke facility service's Boolean expression by the builder of an Invoke facility service. The Boolean expression determines whether the invocation of its related app takes place.