Adobe already has a version of Photoshop available for the iPhone in the App Store, but what if your tastes run more retro than that? Ansca Mobile has taken their Corona iPhone development platform and a copy of Photoshop 1.0, and produced a special version intended for last week’s 20th anniversary of the Adobe app. It allows access to the Photoshop 1.0 Levels panel, taking any image in the iPhone’s gallery and letting you tweak white point, black point and gamma, in separate red/green/blue or combined channels.