tcCalc - timecode & frame calc

# Overview
This app is a calculator specialized for timecode and frame-based calculations. It operates in the same way as a regular calculator, and can calculate timecode and convert between frames.

# Features
- Timecode calculations can be performed with the same feel as a regular calculator.
- Convert between timecode and frames.
- Supports multiple frame rates.
- Input values ​​and calculation results are always automatically adjusted to within the range of 0 to 24 hours.

# How to Use

## Input
Enter timecode and frame count using the number buttons (0-9).
The AC button clears the displayed value and all calculation progress.
The C button clears only the current input value and calculation result.
The Delete button deletes the displayed value one character at a time.
Numbers can be entered up to 8 digits long.

## Calculation
Calculations are performed using the +, -, and = buttons, just like a regular calculator.
For example, you can use the - button to calculate the elapsed time (duration) between two timecodes.

## Display Mode
Press the F button to convert the displayed value to frames.
Press the T button to convert the displayed value to timecode.
You can freely change the display format, even during calculations.

## Changing Frame Rate
Tap the fps display in the upper left corner of the screen to display the frame rate selection screen.
You can choose from 23.98fps, 24fps, 25fps, 29.97fps, 30fps, 50fps, 59.94fps, and 60fps.
29.97fps and 59.94fps use the drop frame (DF) method, while other frame rates use the non-drop frame (NDF) method.
Selecting the hh:mm:ss display allows you to calculate only hours, minutes, and seconds, excluding frames.

## Copy & Paste
Press and hold the calculation result to display a menu with the options to copy or paste.
You can copy or paste numbers by selecting an operation from the menu.
This allows you to copy and paste numbers between the iPhone's standard calculator app, notes app, and other apps.
If the string you are pasting contains non-numeric characters, only the numeric portion will be entered in order.
In frame display mode, the value will be pasted with decimal points truncated.

# Other

## Memory Function
The m+, m−, and mc buttons can be used to access the memory function.
Memorized values ​​are displayed in the upper right corner of the screen, and you can use them as input values ​​by tapping them.
This function is equivalent to the mr button on a typical calculator.

## Calculation History Function
Swipe up on the calculation result display to view the most recent calculation history.
The most recent 20 calculations are saved. If the number of saved calculations exceeds 20, the oldest will be automatically deleted.

## Additional Information
Press the +/− button to change the sign of the input value and calculation result.
Negative values ​​are displayed as 24 hours minus the corresponding value.
Timecode calculation primarily complies with the SMPTE 12M-1 standard.
The 59.94fps calculation is based on the counting method commonly used in Adobe Premiere Pro and other applications.