A friend gave me a first generation smartwatch as a present called the 'Pebble', so I designed a few a square-face version of the Fallout 'Vault-Tec' Industries' watch face for it:
My favorite watchface among those I put together is a revised version of 'Vault-tec 24' by Microbyte: I changed it to look better on a square original Pebble watchface, and to use 12-hour time measurements instead of the grainy/circular 24-hour one it had originally.
Vault-Tec 12 by Blayne: Download
How?: Using image editing software, as well as the Pebble Image Converter to properly dither image resources correctly while not looking too pixelated.
Then upload that .PNG image to the Watchface Generator v2 and add in/control the overall appearance. It lets you choose and adjust just about every conceivable detail.
Afterward, use a QR code reader App to easily open the URL on the phone which is paired to your Pebble watch. I made sure it opened in my default browser, so it could properly hand-off the URL to my Pebble iOS app. From there, as long as there's empty slots in you watch for watch faces, it then automatically transfers the new Watchface to the Pebble by Bluetooth.
Complicated to make, but fun to have.
Original 24h face:
Test shots of various faces on my Pebble + with my original GUESS wide-band leather watchstrap.
For variety, I also created a digital-only face that displays the time and date:
Vault-Tech digital face, white background: Download
Vault-Tech digital face, black background: Download
-Black Background, with logos, text and date: Download
-Black background, no logo text with date: Download
-White background, no text, no date: Download
-Simple RobCo Protectron Digital watchface: Download
While I don't have this loaded currently, but it was a fun exercise in learning the watch face generators features:
Here's a few of the .PNG image resources I made/used/edited. You can recreate any of the watchfaces I made above with specific details using these.
My personal favorite is the "Pipboy 100S", which is coded to show HP as battery remaining, the date, time, and XP as temperature (in Fahrenheit). Download it here.
There's also some excellent other Fallout related watch faces available through the Pebble App.
For other models that support color there's excellent ones like this, which are based on this Fallout 4 fan-poster: