I'm really surprised there is basically only one sleep tracking app for the watch. Even more surprised Apple hasn't offered one theirselves. I use the Sleep ++ app and it's ok but the visuals are no where on par with even Garmin. I will say my favorite feature Sleep ++ has that Garmin does not is a running time of how long you've been asleep, very handy for when the baby wakes you up or the dogs in the morning and you're wondering if you should go back to bed for another hour or stay up. I'd love to see more apps offered in this area.