# IMO Signs vs MARPOL

The clearest difference is review sentiment: IMO Signs at 100% against MARPOL's 0%. MARPOL's advantage is update cadence (every 2 months vs every 95 months) and price ($1.99 vs $3.99). On ads, in-app purchases, monetization model and device support there is nothing between them.

IMO Signs costs $3.99 and MARPOL $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

IMO Signs ships an update every 95 months, MARPOL every 2 months. The most recent releases landed on September 21, 2026 and September 10, 2026 respectively.

## The numbers

| Metric | IMO Signs | MARPOL |
| --- | --- | --- |
| Price | $3.99 | **$1.99** |
| Positive reviews | **100.0% of reviews** | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 95 months | **Every 2 months** |
| Monetization | Paid | Paid |
| Size | 194 MB | 36 MB |
| Requires iOS | 17.6 | **17.5** |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Sergejs Zeigurs](https://appshunter.io/developer/1439812373) | [OLEKSANDR IZERGIN](https://appshunter.io/developer/1678396126) |

## What reviewers say

### IMO Signs

[App page](https://appshunter.io/ios/app/imo-signs/id1439813671)

This educational app allows users to search for symbols by ID or name. It's designed for studying and reinforcing knowledge in a specific subject area. Enjoy a straightforward learning experience.

**Highlights:** Search by ID, Search by Name, Knowledge rechecking, Study aid

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

**In-app purchases:** none


### MARPOL

[App page](https://appshunter.io/ios/app/marpol/id6563146975)

This interactive course covers the MARPOL Convention, including all annexes with detailed visuals. Engage with varied tests to master the material and aim for captain-level knowledge.

**Highlights:** Interactive MARPOL Convention course, All MARPOL Annexes included, Detailed images, Varied tests and tasks, Progress tracking to captain level

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

**In-app purchases:** none


## Frequently asked questions

### Is IMO Signs free?

IMO Signs costs $3.99, with no in-app purchases.

### Is MARPOL free?

MARPOL costs $1.99, with no in-app purchases.

### Do IMO Signs or MARPOL have ads?

Neither IMO Signs nor MARPOL shows ads.

### Which is updated more often, IMO Signs or MARPOL?

IMO Signs ships an update every 95 months, and MARPOL every 2 months. Most recently, IMO Signs was updated on September 21, 2026 and MARPOL on September 10, 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.*