Whether the NetBarrier application is running or not, it is constantly watching for applications attempting to use the network. When an application first attempts to use the network you will see a popup window that tells you the application is trying to make a network connection.
Using the popup window, you can elect to allow an application or block it. Select “Yes” or “No” to configure the application. You might see a name here that you don't recognize. By default NetBarrier does not show a popup for system processes. This should help with some of the most confusing application names, however, some items may still be difficult to identify. If you’re uncertain about what to do, you can click the “I’m Not Sure” button.
You can automatically trust signed software in the NetBarrier Preferences. This will minimize the number of alerts you receive from NetBarrier.