PeakHour is a beautiful, real-time network-traffic visualizer that lives in your menu bar. It provides an instant view of your Internet or WiFi activity in real-time. PeakHour is great for monitoring your Internet or WiFi connection, and can help you determine how much bandwidth your computers and devices are using at any given time.
Note: PeakHour requires a capable, SNMPv1-enabled device to work properly. Many good routers do support SNMP but not all do, so it is important that you check before purchasing. Use the tool in the Related Links to find out if your router is compatible.