Sigma Mk4 app for iPhone and iPad

- Every Day Ease of Use: Simple interface with history mode for expressions and calculations. Ability to use former expressions or values. Haptic feedback provides for a natural calculator feel.
- All Devices. All Modes: Support for light and dark on iPhone and iPad. Dynamic text size support. iCloud sync history, current calculation, programs, and variables across all devices. Multi-tasking on the iPad. Sync across iPhone, iPad, and macOS.
- Financial Calculator: Time Value of Money (TVM) loan calculations with period, interest, present value, future value, and payment. Any four values can be set to compute the remaining variable. Enables easy to use what-if scenarios. Amortization allows computing compound interest, principle, and loan balance.
- Statistics: with one or two variables, x,y predictions, 6 regression models, best-fit regression selection, standard deviation, aggregates, random value generation, permutations, and combinations.
- Cashflow analysis, bonds, interest conversions, margin / markup, breakeven analysis, and more.
- Science and Utility: Trigonometric functions, decimal rounding, display rounding, date functions, roots, powers, and exponentials.
- Menu: Use ⌘ to manage calculation history, settings, and more.
- History and Repeated Calculation: Use = to capture to tape for totals, repeated calculations, and more