Happy birthday! Apple's App Store will officially be five years old on Wednesday, July 10^th. Apple celebrates this wondrous occasion by giving the public some of its most popular apps for free.

Apps that usually go for $20.00 will now be free to download. These apps include "Infinity Blade II," "Tiny Wings," "Barefoot World Atlas," and "Where's My Water?"

Among the now-free apps, perhaps the best discount on an app was for "Traktor DJ," an app that went for $19.99 in exchange for a plethora of tools for mixing and recording music.

For a more extended list of free apps, click here.

USA Today reports that the iTunes App Store originally launched with 500 apps, including Ebay, Facebook, and the timeless classic Super Monkey Ball. Jefferson Graham recounts app users' first app downloads and experiences with them.

With more than 50 billion downloads, CNN declares that the App Store "increased the appeal of the iPhone, and later the iPad, and created a sales model that has been adopted by rivals like Google, Microsoft and BlackBerry in the years since."

Of course, with increased appeal for the iPhone and iPad comes with the decline of the desktops and laptops. The sales of PCs have been grinding to a halt and Microsoft loses momentum as the dominant computing company with the introduction of the App Store. Also, Pandora has been revived and billion-dollar ideas have come from simple dorm-room concepts.

Now, users can enjoy more groundbreaking apps along with the most popular apps already free for the public: Facebook (the social networking app), Instagram (the app that allows users to express themselves through pictures), and Words With Friends (the app that requires a broad vocabulary, strategy, and a stroke of luck).

It is not clear, however, how long users can download the newly-discounted popular apps for free. Be sure to download them within this week to enjoy them for no cost.