Art Authority for iPad, the excellent art history and reference app, is on sale today at 50% off. The app’s price is down from $9.99 to $4.99. I meant to have this post up earlier as it’s been on sale all weekend – but there are still a few hours left to get this great app at a great price.

Here’s a little background on the app:

Art Authority for iPad transports you to an enthralling, real-world art museum filled with works by over 1,000 of the western world’s greatest artists, from ancient times to today. Over 50,000 paintings and sculptures, organized into eight period-specific rooms, each room a gateway to a whole museum’s worth of art. Choose an artist by movement or name, and become instantly immersed in an exhibition devoted just to that artist. Search for and compare different artists’ works by title, subject or location, or just wander at random and get lost in the art.

For more details, you can check out my review of Art Authority for iPad from back in 2010. It’s also an app that we included in our list of Best iPad Apps of 2011.

Here’s an App Store link for Art Authority for iPad.