[josecastillo]

There's a Sensor Watch simulator that demonstrates the features of the various firmware images; this one[1] is running the firmware that shipped with the first boards, and includes a clock, world clock (UTC by default, but customizable by holding the Alarm button), sunrise/sunset, moon phase and temperature. For the sunrise/sunset to work, you'll have to click the "Set Location Register" button, which will prompt for location access.

There are other versions of prebuilt firmware here[2], but my favorite one (even if it's a bit impractical) is the Stargazer firmware[3], whose second watch face can display the locations of the sun, moon and seven planets both in right ascension and declination, as well as altitude and azimuth if you grant location access. We're able to fit a truncated version of the VSOP87 model for planetary motion, right there on your wrist.

[1]: https://www.sensorwatch.net/docs/firmware/simulate/backer/

[2]: https://www.sensorwatch.net/docs/firmware/prebuilt/

[3]: https://www.sensorwatch.net/docs/firmware/simulate/the_starg...