PCalc RPN Calculator has an optional RPN mode and a plethora of conversions built-in, a two-line display, undo and redo, and just about everything else one would expect from a scientific or engineering calculator. Its display is fully customizable and includes themes, various color options, landscape/portrait mode, and more. It’s an expensive calculator but it has an exhaustive set of features.

SimCity for the iPhone is a full featured version of the venerable series. That EA has packed such an immense amount of content, including advisors, help, reports, and all of the zones, utilities, and disasters of the original, is amazing. While the game generally chugs along and could look better, the game play is rewarding and production values are generally top-notch.

Sprocket is a fantastic engineering puzzle game