IPAddressSentinel is a menu bar app which displays and copies your current machines IP addresses and name. (Only the "first" IP address found to save space.) Since the app registers itself to receive notifications of changes in machine IP address, it is always current, and you can use it to know when you Mac is connected to the internet by just looking at your menu bar. If it is not connected then the title will be empty: "-.-.-.-".
No functional limitations, only time limited to 10 days.