Our Mobile App of the Day is Instagram for iOS.

15 million users love Instagram! It's a free, fun, and simple way to make and share gorgeous photos on your iPhone.

Pick from one of several gorgeous filtered effects or tilt-shift blur to breathe a new life into your mobile photos. Transform everyday moments into works of art you'll want to share with friends and family.

Share your photos in a simple photo stream with friends to see - and follow your friends' photos with the click of a single button. Every day you open up Instagram, you'll see new photos from your closest friends, and creative people from around the world.

Features

☆ 100% free custom designed filters and borders such as XPro-II, Earlybird, Rise, Amaro, Hudson, Lo-fi, Sutro, Toaster, Brannan, Inkwell, Walden, Hefe, Nashville, 1977, and others.

☆ Linear and Radial Tilt-Shift blur effects for extra depth of field.

☆ Instant sharing to Facebook, Twitter, Flickr, Tumblr, Foursquare, and Posterous

☆ Unlimited uploads

☆ Interact with friends through giving & receiving likes and comments

☆ Works with first generation, 3G, 3GS and iPhone 4

☆ Full iPhone 4 front & back camera support

☆ And much much more...

Grab Instagram directly from the App Store on your iOS-powered device, or here.