First, please note that I'll be specifically referring to using the Pebble with an Android phone. Due to the developer restrictions in the iOS world, my coworkers and I haven't found iOS apps that interface with the watch to make it do cool things. There's a primitive http tunnel app (HttPebble) that lets watch apps communicate with specially coded websites. But that's all I've seen. (if anyone knows of any, please let me know!) Until things change, I wouldn't bother with a Pebble if you use iOS -- you can't do much more than you could when I wrote my last review. Sure, there are a few watchapps that don't require communication, but those are of limited functionality. And the HttPebble tunnel is limited enough to keep it from being a general solution for integrating with many external websites.
But in the Android world, people have jumped in and written apps to make the Pebble start to fulfill the promise of the "smart" watch. First, I'm still rather unimpressed with the software created by Pebble itself. It takes the development of these 3rd party apps to accomplish what I expected Pebble to actually come up with in the first place.
That being said, there are 2 Android apps that deliver a pretty good "smart watch" experience: Glance for Pebble and Canvas. for Pebble