Rubbernet for Mac

From Conceited Software:

Rubbernet keeps an eye on all network-enabled apps running on your Mac.

Real-time network dashboard
Rubbernet provides real-time monitoring so you can keep an eye on the exact state of your live network connections. With the Activity sidebar, you'll be able to see which applications are currently communicating over your network. When connections are idle, they will dim to let you know that traffic has stopped.

App bandwidth usage
Rubbernet provides a breakdown of per-app network usage, so you can quickly detect apps that phone home, connect to certain servers without your knowledge, or blame the app that's slowing down your network.

Live graphs
Real-time charting displays download and upload transfer rates for all active apps on all monitored Macs. Visualize your network usage and get a bead on network hogs before they get out of control.

Remote monitoring
Monitor all computers on your network from one Rubbernet instance on your Mac. No need to get up and open Rubbernet on a remote Mac to see its network statistics. Unlike other network monitoring tools, there is no complicated setup. It takes just a second to install or uninstall the necessary tools for Rubbernet to work. After that, they sit quietly in the background and provide the app with live data with minimal resource consumption.

Multi-user support
Have multiple user accounts on your Macs? Rubbernet automatically assigns every incoming and outgoing connections to the users they belong to.