I use a Pebble cause the charge lasts 3 plus days and it does pretty much everything I want a smartwatch for.

I use it to:
-Control music/podcasts (especially skipping podcast commercials on the bike or in the shower)
-Quick reply to texts "on my way" "riding now, call you later", etc
-Open voice search when I have bluetooth headphones on (via Tasker)
-Check in to places (yes, I still do this)
-See basic weather forecast
-On-Wrist Google Maps Directions (leave phone screen off, save battery)
-Time my Aeropress steeping
-Set timers, alarms and stopwatches
-Calculator (when my phone is annoying to get at)
-Calendar (both day/date and appointments)
-Tell Time