Pascal: 3-in-1 Calculator
Pascal (formerly Calculator³) is a professional-grade 3-in-1 scientific, graphing, and programmer calculator. It offers a feature-packed scientific calculator for free, along with a Today widget and an Apple Watch app. The graphing calculator and programmer calculator can be unlocked through in-app purchases (IAP), but you can try them out with three trials each. During the trial periods, you have access to all features. To replenish the trial counts, simply reinstall the app.
The scientific calculator supports degree, radian, and gradian modes, as well as decimal factorials, modulo operator, permutations (nPr) and combinations (nCr), standard memory functions, and RPN mode. The graphing calculator, which has a TI-like design, includes all the functions of the scientific calculator and allows you to perform calculations on a smart tape without the need to close parentheses or multiply out brackets. It also offers real-time syntax highlighting and an adaptive sampling algorithm for precise results when plotting graphs. You can show or hide roots/intersections and trace values.
The programmer calculator supports 8, 16, 32, and 64-bit bitwise calculations, as well as binary, octal, decimal, and hexadecimal numeral systems. It also provides Unicode (UTF-16) and ASCII character encoding support. Additionally, it features a binary table that shows the real-time binary representation of the current operand. Like the scientific calculator, it also supports RPN mode.