14. The authoring tool of claim 1 , wherein the fixed aspect ratio and the fixed layout of content defined by the plurality of gallery item descriptors for each of the gallery items is specified by: a gallery component container specifying the fixed aspect ratio for the associated gallery item respectively; and one or more asset component containers each having a fixed position within the fixed aspect ratio of the associated gallery component container respectively.
14. The authoring tool of claim 1 , wherein the fixed aspect ratio and the fixed layout of content defined by the plurality of gallery item descriptors for each of the gallery items is specified by: a gallery component container specifying the fixed aspect ratio for the associated gallery item respectively; and one or more asset component containers each having a fixed position within the fixed aspect ratio of the associated gallery component container respectively. 16. The authoring tool of claim 14 , wherein each of the component containers is arranged to contain or associate one or more of the following: an application function; text; image/photo video; link; location/GPS; widget; and/or feed.