Plugins displays currently installed and downloadable plugins, for WifiAce. There are 2 ways for installing plugins in WifiAce:

1. Download from plugin manager.
2. Paste the extracted plugin in plugin folder of WifiAce.

Plugin manager will download the files form github repository of WifiAce which contains all plugins list. For the later way you would need to restart WifiAce to load them. You need to restart the server to install/remove the plugin.