iPad Missing Apps: Calc XT - a Calculator for the iPad?

The iPad is missing a couple of small but useful utilities when compared to the iPhone or iPod touch. I’m slowly evaluating a number of third-party apps to take their place. The free Bloomberg app is doing a reasonbly nice (but not great) job of replacing the Stock app. The sort-of-free Voice Memos app (99 cents to add the ability to email the recorded audio file) does a reasonable job of replacing Voice Recorder. I’ve been using the free 12c Lite calculator app designed for the iPhone as my iPad calculator.