You need to download and install iShutdown Server.
Once the server is running you can select server startup mode. Automatically or manual (Mac version). Right-click mouse on the iShutdown server icon in taskbar and select preferences to do that.
Your firewall (if installed) must allow network activity for iShutdown server software on port 4505. Else you will not be able to shutdown your host with iShutdown app. If you have troubles with firewall configuration visit our forum and create topic with description of your OS version and Firewall software installed.
Run iShutdown App on your iPhone/iPod/iPad. You will see server in list of your hosts. Now you can shutdown or restart it. It's so easy. Tap on host and select what do you want to do. Shutdown or restart.
You also can install server software on PC using *.msi installer and Active Directories GPO. For "How to" see our forum.