SumSudoku vs Einstein Challenge
Price, ratings, monetisation and update history for both games, side by side — with what reviewers say about each.
SumSudoku
This app offers a logic puzzle experience combining Sudoku and Kakuro elements. Solve grids by filling numbers 1-9, ensuring each appears once per row, column, and box, while also meeting area sum clues. Features include hints, pencilmarks, and progress previews.
- Killer Sudoku puzzles
- Kakuro-style sum clues
- Logic and calculation based
- Hints and pencilmarks
- Progress previews
- Weekly bonus puzzles
- Multiple difficulty levels
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Play a crossover variation of Sudoku and Kakuro! SumSudoku, also known as Killer Sudoku, are addictive logic puzzles best described as a cross between Sudoku and Kakuro. Using pure logic and simple add/subtract calculations, these fascinating puzzles offer endless fun and intellectual entertainment to puzzle fans of all skills and ages. Each puzzle consists of a 9x9 Sudoku grid containing areas surrounded by dark borders. The object is to fill all empty squares so that the numbers 1 to 9 appear exactly once in each row, column and 3x3 box, and the sum of the numbers in each area is equal to the clue in the area's top-left corner. In addition, no number may be used in the same area more than once. The game includes helpful features such as showing possible sum number combinations in an area and pencilmarks to make temporary placement of numbers in the grid. To help see the puzzle progress, graphic previews in the puzzle list show the progress of all puzzles in a volume as they are being solved. A Gallery view option provides these previews in a larger format. For more fun, SumSudoku contains no ads and includes a Weekly Bonus section providing an extra free puzzle each week. PUZZLE FEATURES • 120 free SumSudoku puzzle samples • Extra bonus puzzle published free each week • Multiple difficulty levels from easy to very hard • Puzzle library continuously updates with new content • Manually selected, top quality puzzles • Unique solution for each puzzle • Hours of intellectual challenge and fun • Sharpens logic and improves cognitive skills GAMING FEATURES • No ads • Unlimited check puzzle • Unlimited hints • Show conflicts during gameplay • Unlimited Undo and Redo • Show possible sum combinations option • Pencilmarks feature for solving hard puzzles • Autofill pencilmarks mode • Highlight Excluded Squares option • Lock number on keypad option • Concurrently playing and saving multiple puzzles • Puzzle filtering, sorting and archiving options • Dark Mode support • Graphic previews showing puzzles progress as they are being solved • Portrait and landscape screen support (iPad only) • Track puzzle solving times • Backup & restore puzzle progress to iCloud ABOUT Conceptis SumSudoku have also become popular under other names such as Killer Sudoku, Sumdoku and Sumoku. All puzzles in this app are produced by Conceptis Ltd. - the leading supplier of logic puzzles to printed and electronic gaming media all over the world. On average, more than 20 million Conceptis puzzles are solved each day in newspapers, magazines, books and online as well as on smartphones and tablets across the world. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://www.conceptispuzzles.com/index.aspx?uri=info/doc/220
Einstein Challenge
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It's thought that Albert Einstein in the last century, released the following challenge: In one street there are five houses with different colours. In each one of them, live a person from different nationality. Each one of these people likes a different drink and smokes a brand of cigarettes different from the others. in addition, each one has a different kind of pet. The question is: "who is the owner of the fish". Follow the tips to find the answer.
Screenshots
Verdict
The clearest difference is price: SumSudoku at Free against Einstein Challenge's $0.99. SumSudoku also leads on update cadence (every 5 months vs every 39 months) and iOS requirement (15.6 vs 17.0). Einstein Challenge's advantage is in-app purchases (none vs 10). On device support 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
SumSudoku is free to download; Einstein Challenge costs $0.99 up front. SumSudoku sells 10 one-off in-app purchases. Einstein Challenge asks for nothing beyond the download.
SumSudoku ships an update every 5 months, Einstein Challenge every 39 months. The most recent releases landed on November 2, 2026 and November 3, 2026 respectively.
| Parameter | SumSudoku | Einstein Challenge |
|---|---|---|
| Price | Free — better | $0.99 |
| Rating | 4.8 (815 ratings) — better | — |
| Positive reviews | 96.2% of reviews | — |
| Number of ratings | 815 — better | — |
| Update frequency | Every 5 months — better | Every 39 months |
| Ads | No | — |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | — |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.6 — better | 17.0 |
| Further details — not scored | ||
| Size | 11 MB | 9 MB |
| Age rating | 4+ | 12+ |
| Developer | Conceptis Ltd. | Joao Silva |
Bugs and requests
SumSudoku
Reported bugs
2 issues- Some puzzles have incorrect sums or repeated numbers
- Autofill feature doesn't always work as expected
Requested features
4 requests- Add ability to select difficulty level for weekly bonus puzzles
- Implement a 'dark mode' option
- Allow users to cross out/eliminate number possibilities
- Add a 'one-tap' feature to fill in all 9 numbers in a cell
Einstein Challenge
Not enough reviews yet to summarise bugs or requests.
In-app purchases
SumSudoku
- Easy 1$0.99
- Medium 1$1.99
- Hard 1$1.99
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- Killer 1$1.99
- Medium 2$1.99
- Hard 2$1.99
- Killer 2$1.99
- Hard 3$1.99
- Killer 3$1.99
- Hard 4$1.99
Einstein Challenge
No in-app purchases
Questions
Is SumSudoku free?
Is Einstein Challenge free?
Which is updated more often, SumSudoku or Einstein Challenge?
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