Calclin

A calculator memo app with history that keeps your calculation process visible like a paper roll. Switch between calculator input and formula input to handle everything from everyday math to calculations you want to keep as records.

■ Calculator mode and Formula mode
Calculator mode evaluates left to right (5+5×2=20). Formula mode respects operator precedence (5+5×2=15) and supports parentheses and roots. Switch anytime from the input row, changing the calculation style without leaving the active input area.

■ Paper-roll style history
Expressions and answers stay on the roll from the top, so you can see the flow of your calculation at a glance. Subtle side lines and top shading keep each frame easy to distinguish, even with multiple rolls. In calculator mode, a running total can be shown while you type.

■ Edit rows and add notes
In calculator mode, tap any roll row to edit and recalculate. Add a note to any history entry. Swipe left to delete; swipe right to add a memo, copy the expression, or copy the answer.

■ PDF export
Export a calculation roll as a PDF whenever you want to keep it.

■ Use multiple calculators side by side
Up to a triple deck. Add or remove panels with the [+][−] header buttons, swipe or tap to switch, and double-tap to toggle between 1-panel and 2-panel views.

■ Unit-aware calculations
Calculate with units of length, area, volume, and weight. Press a different unit key to change only the unit, or press the same unit key again to convert the number. Tap an underlined unit to pick from the conversion list.

■ TAX+ and TAX− keys
Add tax to, or remove tax from, the value you are entering or the answer you just calculated. Set up to three tax rates; each key shows its rate.

■ Customizable keyboard
Long-press any key to define it, and merge keys vertically or horizontally to create larger keys. Switch between 5 layouts (30 keys each), and export or import your arrangement.

■ Flexible display settings
Choose the decimal point and grouping symbols, the grouping style (every 3 or 4 digits, Indian style), the number of decimal digits, and the rounding mode (including round half to even). Answers are kept at full precision; rounded answers are marked with "≒", and tapping one shows every digit. Pick Auto, Light, or Dark appearance, and enlarge or reduce text size. Your settings are restored on next launch.

■ Beginner and Expert modes
Beginner mode shows labels and tips for each button. Once you are comfortable, Expert mode unlocks advanced operations such as long-press key editing.

The calculation engine uses C/C++ fixed-point decimal, stored internally in BCD arrays.

Note: Data is not encrypted. Please do not store personal or confidential information.