The Mac App Store took 15 months to get there, but has finally reached 10,000 apps.

Today is a very special day in the App Store world. Exactly three years ago Apple launched the App Store, on July 10, 2009.

As Philip Elmer-DeWitt just noticed, Apple's grandiose App Store celebrated yet another milestone this weekend; its first quarter million apps. As of now, you can find over 250,000 different iOS apps from over 50,000 developers on the Apple App Store, 2 years and 49 days after its launch.

While the developer of Facebook for the iPhone & iPod Touch famously quit in 2009 because he disliked the App store and its policies, the app has lived on.

The iPad App Store has come a long way since it was first unveiled back in March. Launched with just under 1,500 apps, it has grown over the last four months to now surpass the 20,000 apps milestone. Here are the very best.

An app to track a baby's developmental milestones.