Pocket Slide Rule Expert by TestTubeGames icon

Pocket Slide Rule Expert ($0.99) by TestTubeGames is a unique utility app that mimics the operations of the slide rule of old. It allows you to solve problems with 19 different functions and teaches you how to use the device as well.

Pocket Slide Rule Expert by TestTubeGames screenshot

A few months ago my dad presented me with an unexpected gift. It was the slide rule his father used in his profession as a teacher and I was honored that I was to receive it. As I cast my eyes upon the archaic device, I instantly vowed that I would proudly hang it in my office. I was certain I would never learn how to use a device that became obsolete more than a decade before my birth. If you still have no idea what a slide rule is, here is a pretty good explanation.

When I saw that Test Tube Games has recently released an app version of my new favorite heirloom that actually teaches you how to use it, I knew I had to get it.

If you have ever operated a slide rule, there will probably be no surprises when you first touch the virtual version, aside from perhaps how smoothly it works. Line up one notch with another notch, slide the cursor to another notch and obtain a result, theoretically. There is also a brake button that slows down the movements for more precise calculations.

For those who didn’t work in a design office in the 1950s and might actually be interested in learning how to use it, you can tap on the information button. This takes you to a screen that presents a function and two numbers that can be adjusted. Push the solution button and you will be taken back to an active and moving slide rule that adjusts to show you the answer.

You can also select one of the other functions for a similar tutorial. Through this method you can learn how to obtain answers for fairly simple operations. I’m not going to say that I can now operate my own rule, but with concerted effort and time, anyone could learn how to use one.

The practicality of using a virtual slide rule on a 1GHz device to calculate the sum of 3 x 4 is kind of like using the Space Shuttle Endeavor to go to the grocery story. But, there is a high level of nostalgia, and a pinch of practicality to be found in Pocket Slide Rule Expert. And, though the concept may be better served if bundled with other old school calculator apps and called “Retro Calc,” PSRE does exactly what it says it does and is quite fun along the way.

If you want to get a taste of what it does without the risk, you can try the free version first.