The Real Number app for iPhone and iPad

It is a scientific calculator app.
But all I had seen is realistic reproduce established in the 70s. I feel a sense of discomfort and came to make this new calculator app.
I have done all possible check, but I cant guarantee that there is no calculation error or a bug.

(Specifications)
- Fraction, number with square root, number including π, recurring decimal, can be used for display.
It equips currently scientific calculator level (except for the CAS model).
- Internal calculation operations: 16-digit decimal or fraction or irrational number (Not binary floating/double).
It shows whether the result is correct or rounded, by a symbol.
And it has a more exact mode to extend up to 34-digit if the calculation result exceeds 16-digit in addition, subtraction, multiplication, and division.
- Parentheses key [(], [)] are not provided.
By the input like Reverse Polish Notation, it creates new formula using the previous formulas, and automatically adds parentheses, if necessary.
In the other cases, it follows perfectly numerical formula like a general scientific calculator. It is unique, but you will feel higher convenience than the present calculator.
- The touch action direct to the digit in numeric part you want to change, makes numerical input or modify.
And touch action direct to the function in a formula, let you to modify it.
And you can see the hidden part of the formula or the previous formula by touch action.
- This calculator display consists of 2 rows, formula part and numeric part. I think it best operability.
Previous formula re-calculation changing number is easy.
- 4 independent calculators can be switched. (The memories are shared.)
- 20 past formulas are memorized independently in each 4 calculators.
- 27 memories. The memory can hold not only numeric but also formula.
- 35 constants. (CODATA2014)
- Golden Number. When I saw a movie about the mystery of the pyramid, I started to think that the value is necessary in scientific calculator.
- SI prefixes can be inputted and be displayed in result.
- Degree/minute/second, radian, gradian can be used as angle units.
- Copy/paste function of both numerical and formulas.
- iPhone/iPod touch: 10-digit display / iPad: 14-digit display (In exact mode, the answer can accurate up to 34-digit.)
- Selectable decimal point/separator(5) and separator position(4), and numeric(20).
- Multitask (for i-Pad) and Handoff (2 units or more) of iOS are available.
- In the moment you press the key, the pressed number comes.

(Caution: Specifications below are not provided.)
Too much operations defeat basic calculation operation, by confliction of spec, key press times, and key size.
Following items are not included in this app and I have no intention to attach after.
- Perfect textbook display of formula - Computer algebra system(CAS) - Reverse Polish notation input - Programming - Graph - Key touch sound - Probability density - Sample test

Some functions are implemented in my other app. I think these are not convenience on calculator function key and the calculation sheet type app is suitable.
If necessary, please purchase these apps from iTunes store.
- Percentage - Financial - Coordinate transform (Triangle solver) - Equation solver - Hexadecimal,Binary and logic calculation - Date calculation and time calculation - Unit conversion (Imperial units calculation)

I deleted some functions from this app, because of thinking there is no user needs.
- Statistics - List - Matrix - Differential - Integral - Complex number - Random number