You'll see a list of IP addresses appear in the app window after a scan. List of devices currently connected to your network. You can configure the port range that will be scanned, but if you just want to get started, you don't need to mess with any settings. Step 2: After opening the app, follow the tutorial steps, which will initiate your first (and likely a second) network scan. Step 1: Install a copy of Who Is On My WiFi (henceforth known as WIOMW). To get to the root of the issue you can use a free app for Windows. The problem may not be theft, but simply a case of too many devices trying to share a slow connection. You may notice that websites, videos, or file transfers aren't moving as fast as they used to. Sometimes a Wi-Fi password just isn't enough to keep a neighbor or a stranger from stealing your Internet connection.