Nik Software's Snapseed Mobile photo editing app for the iOS is currently Apple's Free App of the Week. The app, normally $4.99, is now available for free download from the iTunes App Store.

A Nik press release says the promotion will last "until June 7, 2012". They don't specify exactly what time on June 7th the promotion ends, so it might be safest to download it today or tomorrow. 

More details on the app itself are available at the Snapseed web site.