How can I find the free app of the day? I'm a Mac user. I want to know which software will help me find the free app of the day in the App Store?

App store always lists the free apps, but it doesn’t display the original price of the applications.
I use Store News which is excellent for finding out price drops and discounted apps.

If you have an iOS device, try AppZapp - allows you to set watch lists, and push notifications and has the ability to track Mac Apps too.