# Tikal-25 — Scientific Calculator

> Scientific calculator emulating a 1978 Japanese model with advanced functions and graph display. (iPhone/iPad app by PETER KOLLNER.)

- Source: https://appshunter.io/ios/app/tikal-25/id6730111959 (this page in markdown: same URL + `.md`)
- Developer: [PETER KOLLNER](https://appshunter.io/developer/1771244599)
- Category: Education, Utilities
- Price: $1.99 (on sale, was $3.99)
- Rating: 5.00/5 from 1 App Store ratings
- Age rating: 4+
- Requires: iOS 17.6 · 6 MB
- Languages: Arabic, Catalan, English, French, German, Japanese, Russian, Chinese, Spanish
- Released: 2024-10-22
- Data updated: 2026-06-04
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/tikal-25/id6730111959/reviews.md

## What is Tikal?

This calculator app is loosely based on a pocket calculator designed in Japan in 1978. It provides arithmetic, trigonometric, logarithmic and statistical functions and fairly high internal precision with a display mode of 8 digits in portrait and 12 digits in landscape mode, which can be interchanged freely while entering numbers, and a scientific notation mode with 5/9 digits mantissa and 2 digits exponent. Internally it uses Decimals for primitive operations and Double floating point numbers for everything else, so in general it should be somehow more accurate than the original calculator model it was based on. I added a graph display for the statistical mode, a shareable calculation log, a manual (all accessible by tapping on the title line above the buttons) and a random number function that produces random numbers in the range [0..1].

The operational correctness is checked with unit tests. All examples from the original manual work with the same or with higher accuracy. There are about 45 unit tests until now covering different combinations, which should be sufficient for everyday educational or household calculations. The unit test set will be further expanded with future versions.

The app does not store or transmit any data apart from the user-initiated log file sharing, it just needs permission to install and use the included 7 segment font for emulating the LCD display. There are no advertisements. The "OFF" Button exits the application immediately. Localizations for other languages are in preparation, this mainly concerns the manual and translations in the additional views. The main display uses a universal standard 7-segment display without localization options for clarity. The dark mode aims at a LED effect instead of LCD. Made the default blue instead of red, though there were no blue LEDs in 1978. In the settings you can choose from red, green or blue for now. 

The localizations may still contain errors and missing translations.

Segment7Standard font license: SIL Open Font License (OFL)
Link: https://www.fontspace.com/segment7-font-f19825

Music in App Previews:  Excerpts from Gustav Holst, "The Planets": "Mercury the Messenger" and "Neptune the Mystic", performed by the London Symphony Orchestra, conducted by Gustav Holst, published by Columbia 1923, Recording in the Public Domain 
Link: https://imslp.org/wiki/The_Planets,_Op.32_(Holst,_Gustav)

Known issues:
- Klingon mode shows an obfuscated log that still does not make much sense.This is because Klingon ist not integrated into Unicode, and logging is probably not compatible with the Klingon honor code anyway.

Written in Swift 5. This application is completely free of AI, so you can be fairly sure only human errors are to be reckoned with...

## Key features

- Emulates 1978 Japanese pocket calculator
- Arithmetic, trigonometric, logarithmic, statistical functions
- High internal precision
- Graph display for statistical mode
- Shareable calculation log
- Customizable display colors (red, green, blue)


## Frequently asked questions about Tikal

### What functions does Tikal-25 offer?

Tikal-25 provides a comprehensive set of functions including arithmetic, trigonometric, logarithmic, and statistical operations. It also features a random number generator.

### How accurate is Tikal-25?

The app uses Decimals for primitive operations and Double floating point numbers for others, offering higher accuracy than its 1978 model inspiration. It has passed approximately 45 unit tests.

### Does Tikal-25 have ads?

No, Tikal-25 is completely free of advertisements. It only requires permission to install its custom 7-segment font for display emulation.

### What devices does Tikal-25 support?

Tikal-25 is available for Mac and iPhone devices, allowing users to perform calculations across different Apple platforms.

### How often is Tikal-25 updated?

The app was last updated on April 1, 2026, with version 1.9. Future versions are planned to expand the unit test set and add more localizations.

### Can I share my calculations with Tikal-25?

Yes, Tikal-25 includes a shareable calculation log feature. You can easily share your computation history with others.

### What is the price of Tikal-25?

Tikal-25 is a paid application, priced at $1.99. This one-time purchase grants access to all its scientific calculator features.

### What is the age rating for Tikal-25?

Tikal-25 has an age rating of 4+, making it suitable for a wide range of users, including children and adults, for educational purposes.

## Version history (last 5 releases)

### 1.9 — 2026-04-01

Fixed a bug that led to crash when a result ending in a .999999... fraction longer than available display size was rendered.

### 1.8 — 2025-11-11

Fixed an error with function calculation on level II, where +/- was not applied correctly and log entries were defect.
Fixed a number of regressions due to a problem with unit test automation in the last few updates

### 1.7 — 2025-10-14

Fixed the App icon

### 1.6 — 2025-10-13

Maintenance, minor improvements

### 1.5 — 2025-09-18

Maintenance upgrade for iPhone 17/ xcode 26

## Apps similar to Tikal

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| --- | --- | --- | --- |
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## More apps by PETER KOLLNER

- [Nudoku](https://appshunter.io/ios/app/nudoku/id6751464305)

All apps by PETER KOLLNER: https://appshunter.io/developer/1771244599

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-04.*