# Sailor's Deck vs Power System Lab

The clearest difference is rating: Sailor's Deck at 5.0 against Power System Lab's 4.0. Sailor's Deck also leads on review sentiment (100% vs 67%) and iOS requirement (15.1 vs 17.0). Power System Lab's advantage is in-app purchases (none vs 3) and update cadence (every 3 days vs every 3 weeks). On price, ads and device support there is nothing between them.

Both are free to download. Sailor's Deck sells 3 one-off in-app purchases. Power System Lab asks for nothing beyond the download.

Sailor's Deck holds the better App Store score, 5.0 against 4.0. Both are backed by a comparable volume of ratings — 1 and 3 respectively. Written reviews point the same way: 100% of Sailor's Deck's written reviews are positive against 67% of Power System Lab's.

Sailor's Deck ships an update every 3 weeks, Power System Lab every 3 days. The most recent releases landed on October 28, 2026 and October 29, 2026 respectively.

## The numbers

| Metric | Sailor's Deck | Power System Lab |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/sailors-deck-colregs/id6761303264/reviews)** | [4.0 (3 ratings)](https://appshunter.io/ios/app/power-system-lab/id6814270423/reviews) |
| Number of ratings | 1 | **3** |
| Positive reviews | **100.0% of reviews** | 66.7% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Every 3 days** |
| Monetization | **Paid** | Subscription |
| Size | 23 MB | 256 MB |
| Requires iOS | **15.1** | 17.0 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 12+ |
| Developer | [Vladimir Arefev](https://appshunter.io/developer/1888773460) | [Serhii Zai](https://appshunter.io/developer/6814270425) |

## What reviewers say

### Sailor's Deck

[App page](https://appshunter.io/ios/app/sailors-deck-colregs/id6761303264)

Master navigation lights and day shapes for skipper exams with this flashcard app. It uses spaced repetition to build lasting visual memory, tracks your progress, and resurfaces difficult configurations until they stick. Study offline with no ads or subscriptions.

**Highlights:** Spaced repetition learning, Four-layer progression of study, Confusion pair training, Offline functionality, Progress tracking and session summaries, Association-specific terminology, Daily streak motivator

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Small Tip | $0.99 | one-time |
| Buy a Coffee | $2.99 | one-time |
| Generous Tip | $3.99 | one-time |


### Power System Lab

[App page](https://appshunter.io/ios/app/power-system-lab/id6814270423)

This app offers a comprehensive learning experience for marine electrical systems through interactive simulations, practical tools, and engaging games. It allows users to explore virtual environments, perform diagnostics, and test their knowledge with various challenges. The app also includes useful calculation tools and customization options.

**Highlights:** Interactive marine electrical simulations, Virtual instruments and diagnostic tools, Four educational games, Electrical calculation tools, Customizable learning environment, Progress tracking and account sync

**In-app purchases:** none


## Frequently asked questions

### Is Sailor's Deck free?

Sailor's Deck is free to download, with in-app purchases available.

### Is Power System Lab free?

Power System Lab is free to download, with no in-app purchases.

### Which has better reviews, Sailor's Deck or Power System Lab?

Sailor's Deck is rated higher. Sailor's Deck averages 5.0 out of 5 from 1 ratings, while Power System Lab averages 4.0 from 3 ratings.

### Do Sailor's Deck or Power System Lab have ads?

Neither Sailor's Deck nor Power System Lab shows ads.

### Which is updated more often, Sailor's Deck or Power System Lab?

Sailor's Deck ships an update every 3 weeks, and Power System Lab every 3 days. Most recently, Sailor's Deck was updated on October 28, 2026 and Power System Lab on October 29, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*