# GyroCop — Compass Error Calculator

> Compass Error Calculator (iPhone/iPad app by Dlyaver Alchik.)

- Source: https://appshunter.io/ios/app/gyrocop/id6765901477 (this page in markdown: same URL + `.md`)
- Developer: [Dlyaver Alchik](https://appshunter.io/developer/1896122064)
- Category: Utilities
- Price: Free
- Age rating: 4+
- Requires: iOS 17.6 · 14 MB
- Languages: English
- Released: 2026-05-11
- Data updated: 2026-06-25
- User reviews in markdown: https://appshunter.io/ios/app/gyrocop/id6765901477/reviews.md

## What is GyroCop?

GyroCop is a practical marine compass check tool designed for seafarers.

The app helps officers perform celestial compass checks using the Sun, Moon, planets and bright stars. It supports clear bridge workflows for calculating magnetic course, deviation and final compass error.

Main features:
• Celestial compass check calculations
• Sun, Moon, planets and bright stars support
• Magnetic course and compass error calculation
• Vessel deviation card storage
• Deviation curve view
• Check history and reports
• Clean dark maritime interface

GyroCop is designed for practical bridge use and training.

Important:
GyroCop is a calculation aid only. It does not replace official navigation equipment, approved onboard procedures, nautical publications, class/company requirements, or the professional judgment of the officer on watch.


## Version history (last 4 releases)

### 1.2 — 2026-06-11

Magnetic compass checks just got sharper.

This update adds automatic magnetic variation calculation using WMM2025 from your entered position and date, plus a new mode for calculating deviation from an observed compass course.

Device GPS position entry is now smoother too: fields lock while updating, then give clear success feedback when the position is applied.

Less manual math, fewer compass-card headaches.

### 1.1.2 — 2026-05-19

Improved compass check accuracy and result presentation.
Added PDF export for compass check reports.
Improved History and Saved Result views.
Improved UTC time input and bearing entry workflow.
Fixed terminology and UI issues.

### 1.1 — 2026-05-17

Improved UTC time handling for compass checks:
• Added seconds to UTC input and result display
• Fixed UTC input to always use 24-hour format, regardless of device AM/PM settings
• Improved nautical formatting for coordinates, headings, variation and deviation
• Added clearer validation for required fields before calculations
• Refined result screen visuals for celestial bodies
• General UI cleanup and stability improvements

### 1.0 — 2026-05-12

No release notes.

## More apps by Dlyaver Alchik

- [RadarCop](https://appshunter.io/ios/app/radarcop/id6768069085)
- [CertCop](https://appshunter.io/ios/app/certcop/id6772711558)

All apps by Dlyaver Alchik: https://appshunter.io/developer/1896122064

## Related topics

[dlyaver alchik](https://appshunter.io/ios/topics/dlyaver-alchik)

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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 2026-06-25.*