It only takes a couple of steps to let you use Off to turn off your computer.
You should be able to turn things off remotely in just a few minutes...
The setup helper will help Off Remote to connect to your computer
(Requires Mac OS X 10.9 or higher)
or see alternative versions (older versions, and versions for other operating systems)
If you use the default firewall on your system, then the helper will configure that correctly.
If you use your own firewall application, then you'll need to make sure it allows Off Remote and Bonjour to communicate through the firewall.
By now, you should be able to see your computer in Off Remote under 'Found Computers'.
Tap on the computer and take control!
If you don't see your computer immediately, you can tap on the rescan button (bottom left of the screen) to re-scan the network
Don't worry if things don't work out immediately. There are a few simple things you can check, and detailed troubleshooting instructions at the troubleshooting page.