# Encyclopedia 3 by Informant vs Openings Mastermind

The clearest difference is review sentiment: Encyclopedia 3 by Informant at 100% against Openings Mastermind's 50%. Encyclopedia 3 by Informant also leads on rating (4.9 vs 4.3) and iOS requirement (8.0 vs 18.6). Openings Mastermind's advantage is in-app purchases (none vs 1) and update cadence (fortnightly vs every 3 months). On price, ratings volume, ads and monetization model there is nothing between them.

Both are free to download. Encyclopedia 3 by Informant sells 1 one-off in-app purchase. Openings Mastermind asks for nothing beyond the download.

Encyclopedia 3 by Informant holds the better App Store score, 4.9 against 4.3. Both are backed by a comparable volume of ratings — 17 and 6 respectively. Written reviews point the same way: 100% of Encyclopedia 3 by Informant's written reviews are positive against 50% of Openings Mastermind's.

Encyclopedia 3 by Informant ships an update every 3 months, Openings Mastermind fortnightly. Both last shipped on October 24, 2026.

## The numbers

| Metric | Encyclopedia 3 by Informant | Openings Mastermind |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.9 (17 ratings)](https://appshunter.io/ios/app/encyclopedia-3-by-informant/id1256485200/reviews)** | [4.3 (6 ratings)](https://appshunter.io/ios/app/openings-mastermind/id6448386251/reviews) |
| Number of ratings | **17** | 6 |
| Positive reviews | **100.0% of reviews** | 50.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 3 months | **Fortnightly** |
| Monetization | Free | Free |
| Size | 44 MB | 88 MB |
| Requires iOS | **8.0** | 18.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Chess King](https://appshunter.io/developer/1096660597) | [Christian Heise](https://appshunter.io/developer/1632898424) |

## What reviewers say

### Encyclopedia 3 by Informant

[App page](https://appshunter.io/ios/app/encyclopedia-3-by-informant/id1256485200)

This educational tool offers systematic chess training with advanced-level combinations for players rated 2400 ELO. It provides interactive lessons, hints, and explanations to improve tactical skills and game knowledge. The app challenges users consistently, unveiling new intricacies as they master specific tactics.

**Highlights:** Advanced level chess combinations, Systematic training by theme, Interactive theoretical lessons, Hints and refutations for mistakes, Play positions against computer, Monitors ELO rating changes, Offline functionality

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Full Course | $9.99 | one-time |


### Openings Mastermind

[App page](https://appshunter.io/ios/app/openings-mastermind/id6448386251)

Master chess openings with this app. Import studies, explore with advanced engines, and practice specific lines through repetition. Track your progress and improve your game.

**Highlights:** Import Lichess Studies or PGNs, Explore openings with Stockfish 15, Practice openings by repetition, Smart practice queue, Track learning progress

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Encyclopedia 3 by Informant free?

Encyclopedia 3 by Informant is free to download, with in-app purchases available.

### Is Openings Mastermind free?

Openings Mastermind is free to download, with no in-app purchases.

### Which has better reviews, Encyclopedia 3 by Informant or Openings Mastermind?

Encyclopedia 3 by Informant is rated higher. Encyclopedia 3 by Informant averages 4.9 out of 5 from 17 ratings, while Openings Mastermind averages 4.3 from 6 ratings.

### Do Encyclopedia 3 by Informant or Openings Mastermind have ads?

Neither Encyclopedia 3 by Informant nor Openings Mastermind shows ads.

### Which is updated more often, Encyclopedia 3 by Informant or Openings Mastermind?

Encyclopedia 3 by Informant ships an update every 3 months, and Openings Mastermind fortnightly. Most recently, Encyclopedia 3 by Informant was updated on October 24, 2026 and Openings Mastermind on October 24, 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.*