From the web, you can sign up and send pages, but an app must be installed on the Mac or Windows PC where you run your slides.
The app requires Windows 7 or later, or Mac OS X 10.10 Yosemite or later. It will also require an Internet connection.
You or your slide tech team will need to download the app from our downloads page and install it. They'll need to login with an account with at least "Receiver" permissions. The app will run in the background, and can be set to start when the computer is started. You can access settings or quit the app from the menu bar on Mac, or the system tray on Windows.