Nonograms Katana: Sharpen your mind!

Nonograms, also known as Hanjie, Griddlers, Picross, Japanese Crosswords, Japanese Puzzles, Pic-a-Pix, "Paint by numbers" and other names, are picture logic puzzles in which cells in a grid must be colored or left blank according to numbers at the side of the grid to reveal a hidden picture. The numbers are a form of discrete tomography that measures how many unbroken lines of filled-in squares there are in any given row or column. For example, a clue of "4 8 3" would mean there are sets of four, eight, and three filled squares, in that order, with at least one blank square between successive groups.
To solve a puzzle, one needs to determine which cells will be boxes and which will be empty. Determining which cells are to be left empty (called spaces) is as important as determining which to fill (called boxes). Later in the solving process, the spaces help determine where a clue (continuing block of boxes and a number in the legend) may spread. Solvers usually use a dot or a cross to mark cells they are certain are spaces.
It is also important never to guess. Only cells that can be determined by logic should be filled. If guessing, a single error can spread over the entire field and completely ruin the solution.

- 1001 nonograms
- All puzzles are free
- All puzzles tested by computer program and have unique solution
- Black-and-white and colored
- Nonograms sorted by groups from 5x5 to 50x50
- Download puzzles sent by other users
- Create and share your own puzzles
- 15 free hints per puzzle
- Use crosses, dots and other symbols to mark cells
- Auto cross out numbers
- Auto fill trivial and completed lines
- Auto save; if you stuck you can try another puzzle and come back later
- Zoom and smooth scrolling
- Lock and zoom number bars
- Lock current puzzle state, check assumptions
- Customize background
- Optional cursor for accurate picking
- Undo and redo
- Share result pictures
- Save game progress to the cloud
- Achievements and leaderboards
- Screen rotation
- Suitable for phones and tablets

VIP Features:
- No Ads
- View Answer
- 5 extra hints per puzzle


What’s New

Version 10.11

- Top 100 of new puzzles
- Minor fixes
- New tools for measurements and assumptions: arrows, letters and other symbols
- Ruler and Eyedropper tools
- Mini game Life! Can be started for any solved puzzle
- New folders in Sent by Users: Started and Solved
- Preserving mode: don't overwrite filled cells
- Scrollable number bars (optional)
- Navigation pads (optional)
- Zoom bar (optional)
- Double tap cursor to flip it
- Flip cursor on the screen edges (optional)
- Snap puzzle to the screen edges (optional)
- Auto scroll on the screen edges while drawing (disabled in strict mode)
- Long tap on a number highlights corresponding segment
- Tutorial
- Enhanced help screen
- View answer for rewarded ad (ad free for VIP)
- Game Center: Achievements and Leaderboards
- And many more

Ratings and Reviews

4.8 out of 5
1K Ratings

1K Ratings

Urtinyfriend ,

Best nonogram by far

I did rare this 5 stars but I would like to see a change. Currently if you make a mistake you can’t tell it’s a mistake until it contradicts something else. And you can go back but you don’t know how far is necessary. You CAN check for ‘correctness’ but the way it does, I couldn’t figure out if it was right or not. It was corrected but I couldn’t tell what it affected. I’d like to see just a highlight of what is wrong and I’d like to correct it so I know what it affects. Also a clue to how many mistakes would be nice. I don’t want to keep playing if there are mistakes.

If there was a counter for number of mistakes and I could just go back till it was zero and figure it out myself, that would be ideal :)

I’ve tried many nonogram apps and this one is my favorite by far. There are others with adventure style play but this one is just simple and I like that.

Purehope22 ,

Best Nonogram ever

I am so glad I found this app. I easily get bored with games so I usually stick to puzzle games but I can easily say this app really satisfies me. Unlike the other app called Picture cross who got lazy with coming up with ideas, u can tell the creators really took their time to create something others would enjoy. I hope they continue to update so we can like and follow people for their content, as I think it’s a great idea to inspire others to create other nonograms themselves. Again, this is an outstanding app. I love it so much and I can easily say that i play this game the most on my phone than my other games lol

JackieBangBang ,

This is THE nonogram app you’re looking for!

I am seriously impressed with this app! This is the first and only app I ever downloaded for logic coloring and I love love love it!!

It’s very helpful and easy to use. They give u a lot of tools to work with and you can adjust settings to your liking so that you can focus and color with ease.

There are endless options and categories of pictures/puzzles to color. At first I was going to start with the easy puzzles and work my way through all of them and then I found all these other categories of puzzles/pictures sent by users so now I will never need to try another app.

At first I was having a hard time registering myself so that I can download the other puzzles. It kept giving me a server error. And I would have only given 4 stars. But it worked for me today I am officially registered and can download! 5 stars for sure. Great great app.

If you’re looking for a nonogram app I promise THIS IS THE ONE. You won’t be disappointed!


Alexander Leontyev
19.2 MB

Requires iOS 8.0 or later. Compatible with iPhone, iPad, and iPod touch.


English, Czech, Dutch, French, German, Italian, Japanese, Korean, Polish, Portuguese, Russian, Simplified Chinese, Spanish, Ukrainian

Age Rating
Infrequent/Mild Medical/Treatment Information
Infrequent/Mild Profanity or Crude Humor
In-App Purchases
  1. VIP version $2.99
  2. 80 Hints $0.99
  3. 200 Hints $1.99


  • Game Center

    Challenge friends and check leaderboards and achievements.

  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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