Last updated on November 27th, 2025 at 12:54 pm
Nonograms Katana – Puzzle Game Review
Nonograms Katana is a Puzzle game from Ucdevs Interaction DOO, first launched in 15th September 2015.
It’s rated 12+ and currently has 6,237+ ratings on the App Store.
What Makes Nonograms Katana Stand Out
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.
Features:
- 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 5×5 to 50×50
- 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
site: https://nonograms-katana.com
facebook: https://www.facebook.com/Nonograms.Katana
This Puzzle game offers engaging gameplay and regular updates for mobile players.
Player Feedback
As a newer release, Nonograms Katana is building its player community. Early feedback suggests .
Recent Updates & Development
Latest Update: 18th November 2025
Recent improvements include:
13.1
- Modern iOS support
- Minor fixes
Download & Availability
Nonograms Katana is available through the official App Store for iOS devices.
Get Nonograms Katana on App Store
Requirements: Requires iPhone 5s / iPad Air / iPad Air (Cellular) / iPad Mini 2 (Retina) / iPad Mini 2 (Retina, Cellular) / iPhone 6 / iPhone 6 Plus / iPad Air 2 / iPad Air 2 (Cellular) / iPad Mini 3 or later.
Compatible with iPhone and iPad devices.
Player Experience Highlights
Community Insight:
It's a little hard to work on nonograms on a cell phone screen, but this app provides a lot of features to make it not only possible but also enjoyable. There are a lot of puzzles (available for free) that result in real pictures. Some puzzles are challenging, but there are also many easier ones to keep the casual puzzler happy.
Fun to guess what the picture is going to be, the best ones dont reveal themselves till the very end.
One of our favorite parts is the user created pictures, but in order for us to keep track of who we like we have to favorite one of their pics. The problem is there are some pics we favorite for other reasons. It would be cool if there was a notification center that would tell you when someone commented on one of your pictures. Despite that, we still love this app and its amazing.
We like that users can create more content and its available for other users to solve.
Ive been using this app for years and we still havent run out of puzzles. Its the only app Ive found that has options for automatically surrounding chunks with Xs, which it says itself may well be too easy, but is really a quality of life necessity when youre doing 50×50 boards. Lots of other great settings too to customize how you want to do the puzzles. Easily worth the extra few bucks to remove ads.
Good range of puzzles and options. Im not sure if its available for phone, but it really needs the screen real estate of an iPad.
Im obsessed with this app. Its challenging, minimal ads, and we love the features that allow us to adjust the screen so we can zoom in, something we were having trouble with other apps because our phone is a 4.5 and our long nails were causing us to accidentally press squares we didnt mean to. We also like the feature that allows you to change the colors, sometimes yellow looks too similar to white when our phone is in night mode and you can adjust the colors to make them darker or brighter. Thank you.
We've been searching high and low looking for a good picross app that doesn't give away the solutions, isn't riddled with lives or microtransactions, and has an intuitive interface. Let us tell you, this app has brought us to the end of our search. Tons of puzzles, tons of options, intuitive interface, no BS, just pure, fun picross designed for the phone. We can't rate this app high enough.
Very well executed interface. Nice features. No ads! And ver good user-created puzzles.
We like that its free and not too easy. Tried other apps where the free part was boring and if you want something harder you have to pay for. Would add the difficulty rating (lets say from 1 to 5 stars). Now nanograms are listed by size only without any difficulty levels. Still definitely recommend over other free apps.
Very addictive game, you will spend a lot of hours playing it.
We love Nonograms, and this app has an excellent, intuitive interface with lots of great options. Please add more puzzles (in-app purchase would be fine).
Im a beginner and as such there arent many puzzles for us in the regular section. But there are home made ones you download from easy to moderate in both b/w and color. Im playing in an iPhone so playing anything larger than 20 x 20 seems impossible although you can expand the playing grid. Ill stick to the under 20 sizes. Thank you for including the amateur ones. Id be lost without them. Well designed with limited ads.
We love this app! We have tried others but this is by far our favorite. We prefer black and white so we wish their were more options or at least an option to clear ALL the puzzles you have completed.
This is very frustrating. We can only play this at home. It says there is no internet connection when Im not connected to WiFi. It doesnt use the regular cell data. But other than that its our fave nonogram interface.
New suggestion, For when you are drawing lines there is a selection of different lines: straight line, box line, and random / non-straight line. A new pattern that would be useful is for there to be a diagonal line. Old Suggestion, which they listened to so thank you we love this app, it has excellent features that are pretty much impossible to find on any other app, one suggestion we have is that for lines that that tell you the numbers (the beige squares) should turn a different color or get darker when that row/column it corresponds with is completed.
Ive tried many and now only use this app for Nonograms.
Everything about this game is basically perfect. Tons of fun.
Our favorite monogram app! We love the new fade out on completed lines.
Ive used a bunch of Nonogram apps. This one has the best and most flexible interface.
Lots of challenging puzzles with minimal adds. Nothing to complain about here.
Our daughter showed us how to play this game, and now its the only game we play. Love it.
The app used to be great. We would have given it 5 stars. However, in the last couple weeks, there have been a couple of animated google banner ads that are really annoying. We know that the developer doesnt really control the ads shown, but the developer is the one who decided to use google ads.
The ads are so distracting. We keep reporting it but its the same ad over and over. It makes us not want to play this game anymore. Please fix the ad content.
Our son in law just showed us this app. Im having fun using it.
This game has a ton of interesting puzzles of varying difficulties, options for color puzzles (an additional layer of complexity), and doesn't interrupt gameplay with ads! Our new favorite puzzle game.
The arbitrary function is a function that lets you fill things in on multiple line without picking up your finger up for each line like most monogram games.
We dont get anything done! We play with our morning coffee on our front porch, we have to set a timer to stop playing! Thats a perfect app. 45 min work commute (by bus) keeps us entertained as well. Ive deleted all other apps like this, this is the perfect user interface. Get it. Buy it. Worth it.
Our favorite nonogram app by far.
Awesome game! Tons of free content. We have completed thousands of puzzles and new ones are added each day.
Like the other reviewers, we can no longer download new puzzles EDIT: its been fixed now!! This is the best nonogram app out there hands down.
We play this app on an android device as well and have enjoyed many hours playing it. We look forward to all of the updates happening on the android platform on the iPhone app as well…it just keeps getting better.
UPDATE 5/26 As of tonight everything seems to be working again. This is our favorite game. We lay in bed and play it for hours pretty much every night while we try to wind down to go to sleep. We love that users can submit new puzzles as those are the most fun. Highly recommend it! initial review It seems they may have stopped supporting this app as the servers seem to be down and the website for the developer also throws a server not responding error. We hope this is wrong as we would love to come back and update our review. This was our favorite app prior to the issues.
These puzzles have delighted us for months and we were anticipating solving them all. We purchased the pro version to get rid of the ads. Thank you Katana! It is working just as before and our finished puzzles are there. Whew! The best game app Ive ever had.
We love this app but the past week or so we cant download any new puzzles sent by users. Seems like there might be a glitch.
We love this app Ive had it for over a year, but its not working lately. We havent been able to open any new puzzles in a few days. Deleted and re-downloaded and its still not downloading the information, so now we have zero puzzles available because its not connecting. Ive never had this issue before. Tried at work and home, wifi and data. Nothing is working.
You know it's a great app when you're devastated that it's not working. Not an update issue, timeouts on both iPad and iPhone. We've purchased it twice, hope you get it back. Ty.
We are really enjoying this game. There are quite a few of the ones out there for these puzzles, but some of them are not as easy to use. This one does an excellent job and is very user-friendly!!! If you like this type of puzzle, we highly recommend.
We truly love this app. We hope there will be more pictures coming. Thank you for this great app.
We love playing these and this is a great app. Only problem is we finished them all. We want more.
Its better on Android(you can save filters for one thing), but its still miles ahead of any other app of this type. Happy to pay for it again on iOS.
This app is great, Ive been playing it for years! But, yesterday, all of the user created puzzles suddenly disappeared! Every category says 0. Any advice.
This has always been our go to game and we love how many new puzzles there are everyday. However, Ive been experiencing trouble downloading new puzzles- we consistently receive the request has timed out notice and have fun out of puzzles to complete as we used to download as we completed them.
We really enjoyed playing this game, but a few days ago it kept saying time request out and wouldnt load. We have tried re-downloading it and continues to not show any puzzles.
Love this game but it randomly stopped working this week, despite uninstall/reinstall. Wont load any games just times out. :(.
We love this app and agree its the best out there, but we just started having issues with it the past couple of days (which is why Im only giving it three stars instead of five). It wont download any new puzzles that we havent done yet and tells us the request has timed out. It upsets us because we havent been able to do ANY new nonagrams on this app. Can anyone help us with this? Im super bummed and want our app back! Ive even deleted it, re-downloaded it, and still nothing. Help.
All of a sudden puzzles will not download, they time out. Very disappointed.
Was our favorite game until recently. Now it timed out when downloading a puzzle. Restarting phone doesnt help. This was the best version available; now cant play at all.
Have played for a very long time. LOVED it EXCEPT it doesnt work any more. For some reason today we are no longer able to download puzzles anymore. Playing on iPhone 8+ and on iPad. Have yet to check on our android device to see if issue is on both platforms.
Should be a 5 star but can no longer download.
User feedback from Apple App Store
App Details
- Version: 13.110
- Size: 12.88 MB
- iOS: 13.0 or later
- Languages: CS, NL, EN, FR, DE, IT, JA, KO, PL, PT, RU, ZH, ES, TR, UK
- Content Advisory: Infrequent/Mild Cartoon or Fantasy Violence, Infrequent/Mild Profanity or Crude Humor
- Developer: Ucdevs Interaction DOO
Last updated: 18th November 2025 | Genre: Puzzle | Developer: Ucdevs Interaction DOO