Oppo Watch or Samsung Gear S both got a rectangular resolution which means the height is not the same as the width
This issue is not yet solved by Watchmaker app since the only resolution supported is either a square or circle shape.
The below video will show the trick to design a full screen resolution faces for rectangular shape watches
Let me know in the comments if this trick is helpful
and also for the owners of the Samsung Gear S if you want me to post another video showing how to install Watchmaker app on the watch