I am now the proud owner of a Pebble Smartwatch (I went for the “Classic” version). It seems to play nicely with my iPhone 5s. My favourite “watchface” at the moment is the built in “time as text” one (although I do think the iWatch one is cool).
I have installed the Pebble SDK and I am going to try to develop an app/watchface or two. Stay tuned.