BitTorrent Sync has nice tools to sync torrents across devices. Instead of having to hit a magnet link or start a download on another device, I can just make sure everything I have or select is ready.

Sometimes you want to have an app on multiple devices to install when you're ready. Maybe you have an automated install that you want to push, or a batch script that depends on having the same file downloaded on multiple devices. This makes managing the same files on multiple devices easier so you can do just that.

It's also helpful if you switch between the desktop, tablet, and smartphone to watch or listen to videos and music. Use an Android emulator if you want mobile on a desktop, and just connect any android device to a television with mini HDMI (or any setup that your android device can understand) if you want to use the TV.