Dentaku: Musical Calculator

In 1981, the German music group Kraftwerk released a song performed on a calculator. The title of the song is "Pocket Calculator" and the Japanese version is titled "Dentaku" (which means calculator in Japanese).

At the time, Japanese calculators were at the peak of their evolution, and it was not uncommon to find models with musical scales assigned to each button, allowing users to play music.

I created this app to celebrate those nostalgia-filled days and to bring a little joy to daily calculation tasks. This app is designed not only as a practical tool but as an experience to be enjoyed through the senses.

Features:

• A musical scale is assigned to each button and even between buttons, producing beautiful sounds as you operate it. You can select from 200 different tones.

• The position of the notes can be easily checked using the "Show Musical Scale" option. (C, C#, D, D#, E, F, F#, G, G#, A, A#, B...)

• Choose your favorite background color. The color changes dynamically based on your tapping speed and gradually returns to the base color when you stop. The transition depends on the original color; for example, a blue background will take on a reddish tint as you tap repeatedly.

• In "Auto Mode," the background color and tone change randomly, keeping every calculation fresh and exciting.

• Save your favorite combinations of tone and color as "My Themes" to recall them at any time.

• While basic functions are based on the standard iOS calculator, unique refinements have been added.

• By default, it uses "Order of Operations" (PEMDAS). When turned off, it behaves like a standard Japanese business calculator.

• Includes an RPN (Reverse Polish Notation) mode. This is a classic fixed-stack specification reminiscent of HP's 4-level RPN, with a customizable stack depth of 4 to 8 levels.

• Supports localized number formats (commas and periods) for various countries.