Is there any software or tool that can give ⌘+` a visual interface just like ⌘+tab does?
Currently there is no option in OS X to give ⌘` a GUI interface. However, you can switch windows of an application using App Exposé.
Go to System Preferences → Trackpad → More Gestures and enable App Exposé.
Use the gesture to evoke App Exposé.
Alternatively, you can install Witch: