Your Apple Watch doesn’t need an iPhone to make it whole.
The new wearable is capable of performing a variety of tasks without a tether to your phone. All it needs is a connection to a familiar Wi-Fi network, and you can start putting it to use even if its iPhone buddy isn’t around.
Sébastien Page at iDownloadBlog gave a thorough rundown, but if you want the quick version, you can:
Message other people

If you’re connected to a Wi-Fi network your Apple Watch already recognizes, you can compose, send and receive iMessages on your Apple Watch. You can also draw sketches, pass along your pulse or tap a buddy using Digital Touch.
Create reminders and calendar events
These two functions work identically, but the upshot is that if you make a new appointment or need a nudge in an hour, your Apple Watch can handle it. For long-term plans, it’ll even store your events locally until you re-sync with your phone. And then it will back everything up to iCloud as normal.
Control your Apple TV

Photo: Apple
Did you lose the tiny remote to your Apple TV and want to watch a movie you rented on iTunes? Good thing you have a backup strapped to your wrist. As long as you’ve done the initial setup, you don’t need your iPhone to control the action.
Get basic information from Siri
Siri still works on your Apple Watch without a phone nearby, so if you need to know when a movie starts or how many inches there are in a kilometer (39,370, if you were wondering), she can help you out.
Check the weather and your stocks

Siri also doesn’t need an iPhone to know which way the wind blows, and she can update you on your portfolio and various sports teams. So if you need to know if it’s going to rain during the football game that you’ve wagered your Starbucks stock on, she can give you all the information you need.