PCalc may not be the longest-lived app in the Apple world (I believe ProVUE Development's Panorama database for Mac may be the winner at 25 years old), but the scientific calculator app from developer James Thomson is pretty darned close. The Mac version of PCalc will be old enough to drink legally in most states -- 21 years to be exact -- in December of 2013, and it has a younger sibling in the iOS world that just received a new coat of paint and a major tuneup for iOS 7.
PCalc 3.0 (US$9.99, universal) can now be switched into a new default iOS 7 th