Might keep your eyes on ZeTime by MyKronoz. I supported this Kickstarter project, and am impressed by mine. Not perfect yet, but Pebble also needed refinement at first. (Now, Pebble now is gold standard for me, to which other smartwatches are compared, including Apple Watch series 2, which I own.) I don’t want to mislead with “glowing” review.
Battery life actually seems better than Pebble (and that is nothing to sneeze at! 10 to 14 days for smart functions!).
Mobile app needs a little more work (for IOS. Can’t speak for Android version.). Notifications are working for me, but dismissing them doesn’t seem to be noticed on iPhone. It still shows them after I have “dismissed” them. On mine, vibration is weak, but that may, or may not be the norm. Other users have reported “Crazy good” vibrations. I have contacted MyKronoz about this and am awaiting response.
Another thing to keep eyes on is battery issues on iPhone (which may be an Apple issue). Mine seems to use iPhone battery what I consider a bit fast. But ZeTime battery is still really good!
Also, they have had an extremely unfortunate shipping issue, that seems to be gradually resolving itself.