MyAddress is a Mac tool that provides you with a quick way to identify your current WAN IP and LAN IP addresses. Besides offering you the aforementioned details, this program also gives you access to information about disk usage, CPU load, network upload and download speeds.
The utility lives on your Menu Bar where you can find the WAN IP and LAN IP addresses and all of the system-related info. The program requires minimum user interaction when it comes to configuring its settings and can easily be used even by beginner Mac users.
Furthermore, you can configure the tool to display notifications or to automatically send you an email as soon as your WAN IP and LAN IP addresses change.
The one thing that bothered me about MyAddress was the fact that it took a while to launch on my Mac. This doesn't necessarily mean that the utility is the problem. It might be my computer's fault as well.
Hence, I'd say it's worth installing this tool on your Mac to monitor your current WAN IP and LAN IP addresses. It's easy-to-use, uses minimum CPU resources, and comes without a price tag.