A GWD file is a watchface design project created by Gear Watch Designer, an application used by developers to create faces for Samsung watches such as Gear S, Gear S2, Gear S3, and Gear Fit2. It contains a design for a watchface which includes the background, index, images, animation, complications (battery, heart rate, workout, etc.), and watch hands.
Gear Watch Designer allows you to edit every detail of the watch face. You can specify the dimensions, placement, angle, font type and size, language, and time format of the watchface. Once you are finished designing your watchface you can build it as a .TPK file then upload it to the Gear store.
NOTE: GWD files created by version 1.2.0 or later cannot be opened by version 1.1.0 or earlier of Gear Watch Designer.