Apple announced today in a short press release that it had sold 1.5 billion iPhone and iPod touch applications during the App Store’s first year of existence. You can nitpick Apple’s timing – technically the store tuned one over the weekend – but the feat is no less impressive considering it’s an improvement of 500 million since it hit the one billion downloads mark less than three months ago, on April 24.

The App Store is one of the primary reasons why the iPhone has been a smashing hit; and in turn the huge install base of around 40 million iPhone and iPod touch devices is further fueling the App Store’s growth. An important factor has been the variety and sheer quantity of applications to choose from. The store currently offers some 65,000 applications, up from 35,000 when last counted, for an average of 370 new applications per day. Sadly, Apple provided no breakdown on how downloads of free apps compare to paid apps.

Apple’s Steve Jobs also noted that the iPhone Developer Program now includes 100,000 members and couldn’t resist a shot across the bow of Palm, RIM and other phone developers looking to get a piece of the action, claiming it’s going to be hard for them to catch up.