STutor vs NinjaSudoku
Price, ratings, monetisation and update history for both games, side by side — with what reviewers say about each.
STutor
This app assists in solving Sudoku puzzles by offering three levels of hints and employing five logical solving strategies. It allows manual puzzle entry or input via an 81-character string, with options to save, recall, and manage puzzles. The app validates entries against its solution and displays possible numbers for incorrect moves.
- Three levels of hints
- Five logical solving strategies
- Manual puzzle entry
- 81-character string input
- Puzzle saving and management
- Entry validation against solution
- Display of possible numbers
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STutor (for SUDOKU TUTOR) is a no-nonsense sudoku solving APP that can display three level of hints while you are solving a puzzle. There are no AD's; no "in-APP-purchases". Just a program to help you advance your Sudoku solving skills. STUTOR solves puzzles using 5 strategies following a logical sequence of methods. The sequence and methods are described in five (5) HELP screens. STUTOR is most appreciated when it displays clues for solving those pesky Friday/Saturday more advanced puzzles. No more disappointing unsolved puzzles. Puzzles are entered manually in a Sudoku grid or by entering (or pasting) an 81 character string. Puzzles can be saved, recalled, changed, deleted, and reordered in the Archive. Upon pressing any of the bottom buttons (except clr), STUTOR will validate and solve the puzzle. Any subsequent user entries will be compared with the solution. A valid entry is entered into the puzzle. If the entry does not correspond to the solution, all the "possibles" or minis are displayed for that cell. If minis are already displayed, the entered number is removed from the minis. Swiping more that two cells in a row will display minis in the row. Ditto for a column or a group. Swiping through more than two rows, columns or groups will display all minis. The "hint" button toggles between a text only hint and one that also displays a clue on the puzzle. The STEP button displays all hint details and alters the puzzle accordingly.
NinjaSudoku
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NinjaSudoku includes - Level 1-5 sudoku generator - Save and play sudoku of your choice - Notes - Undo - Multi-step help - Color mode - Flat, popup free user interface - Ad free - Flight mode friendly
Screenshots
Verdict
The clearest difference is price: NinjaSudoku at Free against STutor's $0.99. STutor's advantage is iOS requirement (13.0 vs 15.6). On update cadence, ads, in-app purchases and 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
NinjaSudoku is free to download; STutor costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.
STutor ships an update every 28 months, NinjaSudoku every 52 months. The most recent releases landed on October 8, 2026 and September 30, 2026 respectively.
| Parameter | STutor | NinjaSudoku |
|---|---|---|
| Price | $0.99 | Free — better |
| Rating | 5.0 (1 ratings) — better | — |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 1 — better | — |
| Update frequency | Every 28 months — better | Every 52 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | — |
| Devices | iPhone, iPod | iPhone, iPad, iPod — better |
| Requires iOS | 13.0 — better | 15.6 |
| Further details — not scored | ||
| Size | 2 MB | 1 MB |
| Age rating | 4+ | 4+ |
| Developer | Robert Carlson | Compiled |
In-app purchases
STutor
No in-app purchases
NinjaSudoku
No in-app purchases









