Use Apple Watch as a handheld Keynote remote?
You'll need to set up the iOS version of Keynote on your iPhone to be a remote control for Keynote on either another iOS device (such as your iPad) or your Mac. To do this, perform the following steps:


On the device that you'll be using to present from, open the remote control configuration:
On iOS, this feature is located in Remote | Devices | Add a Device
On OS X, this feature is located in Keynote | Preferences | Remotes (Ensure that the Enable checkbox is checked)
On the iPhone paired with the Apple Watch, open Keynote and select Remote | Devices | Add a Device
On the Mac or iOS device you'll be presenting from, select the Link button beside the remote device that you wish to use to control presentations
Verify the code shown on the screen, then complete the setup


Once this initial setup has been completed, open the Keynote app on your presenting device and begin a presentation. 

On the Apple Watch, launch the Keynote app. Once the app launches, it will search and connect to the paired Mac or iOS device used for presentations. You'll get a Ready message (Figure A) when you're ready to control a presentation. When you see this message, it means that you can open the presentation on your Mac or iOS device that you'll be presenting.

http://www.techrepublic.com/article/pro-tip-how-to-use-the-apple-watch-to-control-keynote-presentations/