Find Your Lost iPhone
If you routinely leave your iPhone sitting somewhere and you cannot find it, the Apple Watch can help you locate it. This isn't' a full-blown Find My iPhone option that will track it down if it is not close by or if it is stolen, but for forgetful users this is handy.
Swipe up to glances, go to the Settings glance and then tap on the Ping iPhone button at the bottom of the screen. This will ring the iPhone so that you can find it.