Chess Tempo vs Eureka Viewer
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Chess Tempo
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.
- 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
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The Chess Tempo app provides a mobile and tablet friendly interface for Chesstempo features. Supported features: - CHESS TACTICS TRAINING - Improve your tactics by solving tactical problems, with over 100,000 puzzles available. - Both winning and defensive problem types. - For premium members, solve against sophisticated custom sets that target your weaknesses, for example: - Sets that target a particular tactical motif such as pin, fork, discovered attack etc. - Sets that target your previous mistakes, repeating problems until correct. - Spaced repetition sets. - Note, custom sets can be used on the app, but need to be created on the Chesstempo website. - PLAY ONLINE - Play chess against other Chesstempo users. - Supports both live and correspondence games - Get a full post game analysis after every rated game played. Analysis is spread out over our cluster of hundreds of instances of stockfish, allowing high quality results to be returned in a few seconds. - For premium members, have tactics problems extracted from your games, available for solving in the tactics training UI, and selected via the advanced custom sets feature. - OPENING TRAINING - Create multiple black and white repertoires. - Import repertoires from PGN or by entering the moves on the board. - Train your repertoires using spaced repetition. - Limit training to a branch of a repertoire, a single repertoire, or all repertoires of a colour. - Option to restrict training to a limited depth. - Ability to train against the moves that are proving the most resistant to spaced repetition learning. - Comment on each position or move, and read the comments others have chosen to make public. - Add engine evaluations or annotations such as +=, ?! etc to each move in the repertoire. - Export repertoire and your comments and annotations to PGN. - Graphs showing learning status and progress over time. - Use the opening explorer to choose moves for your repertoire (limited to a depth of 10 moves for free members). - For premium members, the ability to use the cloud engine to ask for analysis on any position. - ENDGAME TRAINING - Practice endgames from 3, 4, 5 , 6 and 7 piece endgame positions extracted from real games. - Over 14000 different positions. - 2 positions per day for free members. - For premium members: - More positions available per day. - Custom sets that can target a particular endgame type, endgames you keep getting wrong, or utilise spaced repetition for training. Note: Some custom sets types need to be created on the Chesstempo website before being used on the app. - GUESS THE MOVE - Learn by playing through master games and get scored on how well you match the master's moves. - ANALYSIS BOARD - Analyse positions using our cloud engines (requires premium membership). Cloud engines allow you to run high quality analysis without using up your own device's battery. Diamond members can request up to 8 analysis threads, analysing many times more positions per second than an engine running on your device could provide. - Setup positions from FEN or by arranging the pieces on the board with the board editor. - Analyse tactics problems after completion to better understand the solution. - PREMIUM SUBSCRIPTIONS - Monthly auto-renew subscriptions are provided via in app purchases for Silver, Gold and Diamond memberships, providing access to more powerful training features. Details of features provided are shown within the app. - Payment will be charged to your Apple ID account at the confirmation of purchase. The subscription automatically renews unless it is canceled at least 24 hours before the end of the current period. Your account will be charged for renewal within 24 hours prior to the end of the current period. You can manage and cancel your subscriptions by going to your App Store account settings after purchase. Terms of Service: chesstempo.com/tos.html
Eureka Viewer
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.
- 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)
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Eureka! is an eReader designed exclusively for reading and annotating digitally protected pdf documents, and viewing videos distributed through ArchiMedia Advantage, Inc. platforms. The Eureka! eReader provides fast and secure access to your digitally protected pdf materials distributed via ArchiMedia Advantage, Inc. platforms. To ensure the application enhances the use of your licensed materials, it is optimized to display statistical and mathematical content . For use online or offline (limited terms), Eureka! simulates traditional study techniques like highlighting, underlining, margin notes (comments) and provides the option to enter your own notes (by page). All of these tools are automatically captured in an annotation index for easy reference and sync across compatible devices! Document printing, if authorized, is available exclusively through use of a Eureka! desktop offline player; printing from web browsers or mobile devices is not available. With quick load times, responsive page navigation, and viewing options such as zoom, single page, and side by side, Eureka! is ideal for intensive study and will quickly become your preferred tool for consuming digitally published content at home and on-the-go.
Screenshots
Verdict
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.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
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.
| Parameter | Chess Tempo | Eureka Viewer |
|---|---|---|
| Price | Free | Free |
| Rating | 4.0 (113 ratings) — better | 2.5 (11 ratings) |
| Positive reviews | 58.1% of reviews — better | 0.0% of reviews |
| Number of ratings | 113 — better | 11 |
| Update frequency | Monthly — better | Every 3 months |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.0 | 15.0 |
| Further details — not scored | ||
| Size | 27 MB | 261 MB |
| Age rating | 4+ | 4+ |
| Developer | Chess Tempo | ArchiMedia Advantage Inc. |
Customer experience
Chess Tempo
Eureka Viewer
Bugs and requests
Chess Tempo
Reported bugs
42 issues- 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
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- Engine takes too long to make moves
- Tactics page crashes
- Bug in solving history (last 50 tactics not showing)
- Endgame training seems buggy, cannot make moves
- Registration process has issues (username/email taken)
- Loading times are very long
- Misclicks are not correctable
- Difficulty levels are inconsistent after a while
- App is not a native app, feels like a website
- Board and pieces are too small/large on different devices
- Does not accept alternate right moves
- Game aborted/resigned frequently
- Missing endgame feature in app
- Doesn't show number of problems done
- UI is awkward and slow
- Misclicks are hard to correct
- Tapping opponent's pieces is problematic
- Buttons are too close together (skip/retry)
- Tactics page crashes
- Engine move takes too long
- Misclicks are not correctable
- No clear instructions
- Difficulty levels are the same after a while
- Loading times are very long
- Tactics are too computer-like
- Puzzles are overrated/underrated
- UI is horrible and alien-like
- Puzzles are too difficult for average person
- Rating of puzzles is questionable
- Punished for solving correctly but too slowly
- UI is awkward and slow
- Not as user-friendly as others
- Game aborted/resigned frequently
- Missing endgame feature in app
- Doesn't show number of problems done
- Board and pieces too small/large
- Does not accept alternate right moves
Requested features
19 requests- 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
Show 14 moreShow fewer
- Add a dark mode
- Improve board and piece sizing for different devices
- Allow alternate right moves
- Add an abort option for games
- Fix bug in tactic history
- Allow viewing and creating comments for problems
- Improve endgame training functionality
- Show number of problems done
- Make registration process smoother
- Allow users to select a comfortable difficulty range
- Improve the spaced repetition intervals
- Add a feature to customize intervals
- Make the app feel more like a native app
- Improve the UX significantly
Eureka Viewer
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Chess Tempo
- Silver membership - 1 month$2.991 Month
- Gold membership - 1 month$3.991 Month
- Diamond membership - 1 month$8.991 Month
Eureka Viewer
No in-app purchases
Questions
Is Chess Tempo free?
Is Eureka Viewer free?
Which has better reviews, Chess Tempo or Eureka Viewer?
Do Chess Tempo or Eureka Viewer have ads?
Which is updated more often, Chess Tempo or Eureka Viewer?
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