There's a couple of other watch apps that will display multiple time zones, but I wanted to see if I could create a watchface that would be simpler to use. Here's the watchface I ended up with:
DualTZ has two parts:
- A regular app to configure the watchface. It lets the user pick a timezone, which is then stored on the phone using httpebble.
- A watchface that uses httpebble to retrieve the local timezone offset, and the remote timezone that the user selected.
Right now it's still a little rough around the edges. The timezone names I'm using come from the tz database, and could be a little more fine-grained. 12-hour mode is only partially implemented. There's a handful of errors that aren't properly handled. It's the largest chunk of C code I've ever written and looks horribly disgusting inside. But it does seem to mostly work, at least for me.
Binaries for iOS and Android are at mypebblefaces. Source is now on github.
UPDATE FOR 2.0
I've rewritten the way the app stores data on the phone. Anybody upgrading from previous version will need to re-run the selector. Sorry. :-(