Wireless Network Watcher is a small, lightweight utility, which scans your wireless network and then displays a list of all devices that are currently connected to your network.
The app shows detailed information about any connected device including: IP address, MAC address, the network card manufacturer, and (optionally) the computer name. If you need to transfer this data, then you can also export the connected device list into html/xml/csv/text file, or copy the list to the clipboard and then paste into a spreadsheet app.
Overall, Wireless Network Watcher is nice little information tool that gives you a window into your network. It can’t, however, provide any methods to block or ban intruders.