- By Apple watch you can pair an external Bluetooth heart rate, That could make the watch a killer health and medical gadget, because by apple watch you could pair other types of devices in the future.

-By Apple watch You can take screenshots.

- You can restore the data if it removed by using a local backup on your phone, Your settings and apps get put back on again, and everything feels the same as when you last left it. I did this once, and it worked just fine.

- Unfortunately You can't use apple watch to start and stop the calls on your iPhone, but it may change and update this technology, but  you can make and answer calls on the Apple Watch, and then hand them off to your iPhone to continue the call there.

- Apple watch can pay for things without pay. This could be a huge help at many places that don't accept Apple Pay, or to use for airline tickets or concerts.

You can pay for things without Apple Pay, you can add QR codes via your phone and use them on the Apple Watch, put Starbucks card into the watch and paid.

- You can't find other watch-faces to download and install. Not yet, at least, and it hasn't been revealed when or how watch-faces might be sold, but don't forget that Apple's 10 watch faces are beautiful, and incredibly designed, and it hasn't been revealed when or how watch-faces might be sold.

- If the battery  watch too low, you can keep your watch in a pared-down mode that just tells the time, nothing else, and if you want to deactivate Power Reserve, you need to reboot the watch.