| golang.org/x/mobile/event/size | Package size defines an event for the dimensions, physical resolution and orientation of the app's window. | 
    | golang.org/x/mobile/exp/gl/glutil | Package glutil implements OpenGL utility functions. | 
    | golang.org/x/mobile/geom | Package geom defines a two-dimensional coordinate system. | 
    | image | Package image implements a basic 2-D image library. | 
    | image/color | Package color implements a basic color library. | 
    | image/draw | Package draw provides image composition functions. | 
    | time | Package time provides functionality for measuring and displaying time. |