WhatsMyIP.pro is described as 'is the best site for quick and easy viewing of your public IP address'. There are five alternatives to WhatsMyIP.pro, not only websites but also apps for a variety of platforms, including Windows, Linux, Mac and iPhone. The best alternative is ShowIP, which is both free and Open Source. Other great sites and apps similar to WhatsMyIP.pro are Geo IP Tool (Free), whatismyip.cc (Free), My Public IP (Paid) and TrueIP (Free).
My Public IP is a utility to let you know through which internet IP the world see you. This is what is usually called your public IP. This 'Public IP' some time can be static but more often it is assigned by your provider anytime you connect for a new time.