Ninekeep vs CROSSUP
Price, ratings, monetisation and update history for both games, side by side — with what reviewers say about each.
Ninekeep
This Sudoku game focuses on teaching you advanced solving techniques. It offers classic and Sums modes with customizable difficulty. Earn in-game currency to unlock new themes without any forced ads.
- Teaches Sudoku solving techniques
- Classic and Sums (Killer Sudoku) modes
- Customizable difficulty levels
- Unlimited puzzle generation
- Daily Ledger for tracking progress
- Unlockable themes via in-game currency
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Ninekeep is a sudoku game that explains its own hints. Ask for one and it names the solving technique the board needs, then shows you the cells it applies to. You still decide whether to place the digit. The home screen carries today's puzzle, your current streak, and the way into both modes. TWO WAYS TO PLAY Classic is the nine-by-nine grid you know, at four difficulty levels from Easy to Expert, each keeping its own best time. Sums (the variant usually called Killer Sudoku) starts with no given digits. The grid is drawn into cages instead, each printed with the total its squares add up to, and you work back from that. Sums has its own four difficulties and best times. HINTS THAT TEACH Thirteen solving techniques sit in the ladder, from naked singles up through X-Wing, Y-Wing, Swordfish and Colouring. A hint names the technique that applies and points you at the cells it works on. It explains why the technique holds there before it will place anything. Solve using a technique without help and the app records that you can do it. BOARDS BUILT ON YOUR DEVICE Every puzzle is generated on your device, so the supply keeps going and the daily arrives fresh. Difficulty means something specific here: a Hard board genuinely needs the techniques the word implies, rather than just showing fewer numbers. THE DAILY LEDGER One puzzle a day seals into your Ledger when you finish it, and the year fills in as you go. A missed day can still be sealed later, and a quiet evening reminder is there if you want it. The Ledger opens on your current streak, your best time on Hard, and the share of boards you finished cleanly. Under those sit the last thirty days, a twelve-week chart of solve times, and your averages by difficulty. MARKS AND THE BINDERY Solved boards earn Marks, and harder boards earn more: two for Easy, fourteen for Expert. The Bindery is where you spend them. Marks buy papers that re-skin the board and the frame around it, and foils that change your daily seal's finish. Solving is the only thing that mints them. HOW MUCH THE GRID HELPS On Easy and Medium boards, Fill writes every pencil mark for the cost of a hint, and marks tidy up as you place digits. Conflicts can highlight themselves. Selecting a number can light every cell that already holds it, and the tray can count what is left. You can hide the timer. Challenge mode caps you at three mistakes, three hints per board, or both. Reach a cap and the run ends where it stands; you can restart the same board, and boards you already sealed keep their times and Marks. ON YOUR HOME SCREEN A Home and Lock Screen widget carries your streak and whether today's board is sealed. You can start it from Siri or Spotlight. Your Ledger syncs between iPhone and iPad through your own iCloud account; signing in on both is the whole setup. WHAT THINGS COST Two hints per board come with the game, along with pencil notes, auto-check, retries, and an undo. For another hint after that, watch a short video, or buy Remove Ads once and the extra hints simply apply. A banner sits on the home and settings screens, and one full-screen ad plays after a board seals, on the way back home. That ad waits until you have played two sessions and sealed five boards, and nothing plays while you are solving. Remove Ads takes both away for good. Streak restore always asks for a short video, and Marks come from solving alone, so neither an ad nor a purchase will repair a streak or improve a time. ON IPAD Built for the screen rather than stretched across it: three panes and a side keypad. The board comes in dark and light finishes. Sound and haptics are yours to keep or turn off. ACCESSIBILITY The board is drawn for a dark interface, and every digit, mark and control holds its contrast against it. Each number can take a color of its own in the keypad, and Settings carries its own switches for motion and transparency, so you can quiet the animation and the layering from inside the app.
CROSSUP
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CROSSUP is the elegant crossword app to relax and keep your mind sharp – with thousands of handcrafted puzzles in large, easy-to-read type. • A new crossword every day – five difficulty levels from Beginner to Expert • More daily puzzles: arrowword (Swedish style), word search and anagrams • 40 themed categories: animals, nature, food, sport, music, film and many more • Collect coins and unlock hints whenever you get stuck • Earn badges, complete missions, keep your daily streak and level up • Choose from 15 refined premium themes and 10 colour worlds • Four languages: English, German, Spanish, French • Large cells and clear type – easy on the eyes Perfect for anyone who loves a good puzzle – with your coffee, on the train or on the sofa. Enjoy!
Screenshots
Verdict
The clearest difference is in-app purchases: Ninekeep at none against CROSSUP's 10. CROSSUP's advantage is ads (none vs shown) and iOS requirement (15.0 vs 17.0). On price, update cadence 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
Both are free to download. CROSSUP sells 10 one-off in-app purchases. Ninekeep asks for nothing beyond the download.
Ninekeep ships an update monthly, CROSSUP every 6 weeks. Both last shipped on October 31, 2026.
| Parameter | Ninekeep | CROSSUP |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (2 ratings) — better | — |
| Number of ratings | 2 — better | — |
| Update frequency | Monthly — better | Every 6 weeks |
| Ads | Yes | No — better |
| In-app purchases | No — better | Yes |
| Monetization | Free with in-app purchases | — |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 17.0 | 15.0 — better |
| Further details — not scored | ||
| Size | 13 MB | 20 MB |
| Age rating | 4+ | 4+ |
| Developer | Velcairn Studios LLC | Nikolai Schramenko |
In-app purchases
Ninekeep
No in-app purchases
CROSSUP
- Ocean Breeze$1.99
- Royal Library$1.99
- Emerald Palace$1.99
Show 7 moreShow fewer
- Lavender Fields$1.99
- Sunset Coast$1.99
- Midnight Black$1.99
- Japanese Zen$1.99
- Arctic Blue$1.99
- Vintage Newspaper$1.99
- Luxury Gold$1.99









