Extra dial in themes is something that’s shown on top of the clock face. It can be one of 4 things:
1. As the name suggests it is a secondary dial around the edges. Theme SplitC24 in Pack 13 for example (but many others) might include the minutes dial optionally, as an extra. So you can turn it off for a cleaner look, which actually makes more sense (e.g. on the TicWatch which already has the minutes around the bezel).
3. Also some of the watch face themes leave the center of the face empty (where the hands meet) since this is the part of the watch face which has pixels always lit up, and hence most AOD burn in happens in the center of the screen.
So I give an option to keep the center empty in certain themes, but with the “Extra dial” you can put that center dot back (e.g. in the analog themes of Pack 7)
4. The trickiest use of this “extra” piece is actually in the extra corner pieces for square watches (Zen Watch 2, Oppo watch, Polar M600). This is also in Theme Pack 7
Options to control secondary dial (“extra”) component visibility in clock bubble settings (on watch and phone)
Custom “extra dial”
The overflow menu in Clock Bubble dialog lets you provide your own custom “extra” components (active and low power/ambient variants). Use any square shaped PNG in the size of the whole clock bubble (e.g. 400×400) that includes transparent areas (alpha channel) →