# Chess Tempo vs Eureka Viewer

The clearest difference is review sentiment: Chess Tempo at 58% against Eureka Viewer's 0%. Chess Tempo also leads on rating (4.0 vs 2.5) and update cadence (monthly vs every 3 months). Eureka Viewer's advantage is in-app purchases (none vs 3). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Chess Tempo sells 3 in-app purchases, starting at $2.99 per month. Eureka Viewer asks for nothing beyond the download.

Chess Tempo holds the better App Store score, 4.0 against 2.5. That said, the two scores are not equally well evidenced: Chess Tempo has 113 ratings behind it against 11, so its average is the more settled of the two. Written reviews point the same way: 58% of Chess Tempo's written reviews are positive against 0% of Eureka Viewer's.

Chess Tempo ships an update monthly, Eureka Viewer every 3 months. The most recent releases landed on November 6, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | Chess Tempo | Eureka Viewer |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.0 (113 ratings)](https://appshunter.io/ios/app/chess-tempo-chess-tactics/id1441878094/reviews)** | [2.5 (11 ratings)](https://appshunter.io/ios/app/eureka-viewer/id1532773030/reviews) |
| Number of ratings | **113** | 11 |
| Positive reviews | **58.1% of reviews** | 0.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Monthly** | Every 3 months |
| Monetization | Free with in-app purchases | **Free** |
| Size | 27 MB | 261 MB |
| Requires iOS | 15.0 | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Chess Tempo](https://appshunter.io/developer/1441878093) | [ArchiMedia Advantage Inc.](https://appshunter.io/developer/1532773032) |

## What reviewers say

### Chess Tempo

[App page](https://appshunter.io/ios/app/chess-tempo-chess-tactics/id1441878094)

Enhance your chess skills with a comprehensive training suite. Solve over 100,000 tactical puzzles, practice openings and endgames, and play against other users. Analyze games with powerful engines and track your progress.

**Highlights:** Tactics training with 100,000+ puzzles, Opening repertoire creation and training, Endgame practice with real game positions, Online chess play (live and correspondence), Post-game analysis with cloud engines, Guess the move from master games, Analysis board

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Silver membership - 1 month | $2.99 | per month |
| Gold membership - 1 month | $3.99 | per month |
| Diamond membership - 1 month | $8.99 | per month |

**What reviewers like**

- 👍 Excellent tactics training
- 👍 Great for serious chess improvement
- 👍 Wide variety of tactics
- 👍 Useful comments on puzzles
- 👍 Good value for money (for subscribers)

**What reviewers complain about**

- 👎 Expensive subscription ($20/month)
- 👎 No free limited play option
- 👎 Bait and switch pricing
- 👎 UI is confusing and abysmal
- 👎 Difficult to navigate

**Reported bugs**

- Cannot connect to server
- Connection issues when opening the app
- Bug makes engine take ~5 seconds to make its move
- App quits whenever tactics page is opened
- Data loss

**Requested features**

- Move buttons to improve usability
- Add a takeback option to correct misclicks
- Improve UI for better bullet play
- Make UI more intuitive and user-friendly
- Provide explanations for icons and functions


### Eureka Viewer

[App page](https://appshunter.io/ios/app/eureka-viewer/id1532773030)

This eReader allows secure access and annotation of digitally protected PDF documents from specific platforms. It offers tools like highlighting, underlining, and note-taking, with an automatic index for easy reference and cross-device syncing. Optimized for statistical and mathematical content, it's ideal for intensive study.

**Highlights:** Secure access to protected PDFs, Highlighting and underlining, Margin notes and custom page notes, Automatic annotation index, Cross-device syncing, Optimized for statistical/mathematical content, Offline access (limited terms)

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Chess Tempo free?

Chess Tempo is free to download, with in-app purchases available.

### Is Eureka Viewer free?

Eureka Viewer is free to download, with no in-app purchases.

### Which has better reviews, Chess Tempo or Eureka Viewer?

Chess Tempo is rated higher. Chess Tempo averages 4.0 out of 5 from 113 ratings, while Eureka Viewer averages 2.5 from 11 ratings.

### Do Chess Tempo or Eureka Viewer have ads?

Neither Chess Tempo nor Eureka Viewer shows ads.

### Which is updated more often, Chess Tempo or Eureka Viewer?

Chess Tempo ships an update monthly, and Eureka Viewer every 3 months. Most recently, Chess Tempo was updated on November 6, 2026 and Eureka Viewer on November 3, 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.*