`GtkAppChooser` is an interface for widgets which allow the user to choose an application.
The main objects that implement this interface are [class@Gtk.AppChooserWidget], [class@Gtk.AppChooserDialog] and [ class@Gtk.AppChooserButton].
Applications are represented by GIO `GAppInfo` objects here. GIO has a concept of recommended and fallback applications for a given content type. Recommended applications are those that claim to handle the content type itself, while fallback also includes applications that handle a more generic content type. GIO also knows the default and last-used application for a given content type. The `GtkAppChooserWidget` provides detailed control over whether the shown list of applications should include default, recommended or fallback applications.
To obtain the application that has been selected in a `GtkAppChooser`, use [method@Gtk.AppChooser.get_app_info].