Cool watch. Have mine for a while. Would recommend. I love battery time (around 2 weeks with my usage patterns with longer backlight time). Love variability and flexibility of watchfaces. Comparing to my usecases of applewatch I am missing "find my phone" (which is mentioned to be under development) and paying with the watch. Yet increased battery life + hackability compensates those for me.
Hacking your own app is also something easily accessible. When I preordered the watch I thought of a breathing app which could be used with closed eyes. App must indicate breathing phase with vibrations. Guess what? In couple days I got first version running and published (couple more weeks of polishing completely transformed the initial version which still has screenshots in the project folder for historical reasons). In case you also want to meditate/box-breach with your pebble here is it free on any charge