TZYX is a simple stack logic calculator for iOS. The layout and functionality was inspired by the great Hewlett-Packard 42S RPN Scientific calculator, but its functionality has been simplified to that of a standard pocket calculator.
The calculator makes use of stack logic, or reverse polish notation, for calculations. An explanation of how RPN works is beyond the scope of this readme, but in essence this calculator works similarly to most HP calculators, so if you've used one before, you should be at home with TZYX.
This was my second iOS app, and I personally wanted a basic stack logic calculator app on my phone for calculating tips, etc. Of course, there are alternatives on the app store, but making my own app was good practice. Initially, I started off with a completely object-oriented approach, but abandoned this due to my inexperience with Swift.
You should be able to sideload the app on an iPhone 6 running iOS 9.0+ by building it with Xcode 7. If you attempt this, please let me know what you think. Any feedback will be valuable.