Providing complications on an electronic watch

A method of providing data by a companion device to a wearable device, the method comprising, at the companion device:

• receiving, from the wearable device, a list of applications that are assigned to display windows on a display currently being used by the wearable device, the list of applications including a first application;
• receiving, from the first application on the companion device, a request to send new complication data to the wearable device;
• accessing the list of applications to determine that the first application is assigned to a complication on the display currently being used by the wearable device;
• and
• responsive to the first application being assigned to the complication, sending the new complication data to a transport daemon for transmitting to the wearable device.

An wearable device comprising:

• one or more processors configured to:
• provide a user interface for a user to configure data to be displayed in one or more style windows in combination with a time on a display;
• receive a first window selection of a first style window of the display, the first style window associated with a first plurality of templates for displaying the data;
• identify a first list of applications designated as supporting the first style window;
• provide the first list of applications to the user;
• receive a first application selection of a first application from the first list of applications;
• responsive to the first application being assigned to the first style window, receive, from the first application, a first data object specifying a first template of the first plurality of templates and one or more first data items for displaying according to the first template;
• retrieve the first template;
• and
• display the one or more first data items in the first style window on the display according to the first template.