Image processing apparatuses have a unit for registering settings in applications or a unit for registering application settings on a portal screen, but do not allow these units to function in a coordinated manner. For example, if a user who frequently uses a certain application registers settings of the application, the settings may also be useful to other users. However, users who mainly use their own portal screens cannot invoke the settings. Settings of an application registered as a shared custom button are automatically registered as frequently used settings in the application. Similarly, settings registered as frequently used settings in an application are automatically registered as a shared custom button.