GlassWire operates on a "Freemium" model. The free version is fantastic. It allows you to monitor your network, see which devices are connected, and view your bandwidth history. But the Premium version unlocks the features that security nerds crave:
Use the official free version, wait for a sale, or purchase a discounted bundle. If you absolutely cannot pay, stick to open-source alternatives. But never, ever run an untrusted executable just to unlock a graph. glasswire premium key