Instagram passed a new milestone on Wednesday: For the first time ever it is now the number one most downloaded free application in Apple’s iTunes App Store. Of course, the company announced an even bigger milestone earlier this week when it was acquired by Facebook for $1 billion — or about $77 million per employee that works there. Not bad considering Instagram was only started two years ago and had yet to create a profitable business model.

Instagram also released a new update for its Android application on Wednesday that adds support for NVIDIA’s quad-core Tegra 3 processor. The update is available now for free from Google Play and probably really only applies to owners of the HTC One X right now.

[via Instagram, Mobile Burn]