# 0h n0 > Logic puzzle game with dot placement and grid completion. (iPhone/iPad app by Q42 B.V..) - Source: https://appshunter.io/ios/app/0h-n0/id957191082 (this page in markdown: same URL + `.md`) - Developer: [Q42 B.V.](https://appshunter.io/developer/385525157) - Category: Games, Entertainment, Puzzle - Price: Free with in-app purchases - Rating: 4.90/5 from 122 App Store ratings · 36 written reviews indexed - Age rating: 4+ - Requires: iOS 8.0 · 3 MB - Languages: American English - Released: 2015-02-12 - Data updated: 2026-07-05 - Monetization: free with in-app purchases - User reviews in markdown: https://appshunter.io/ios/app/0h-n0/id957191082/reviews.md ## What is 0h n0? It's 0h h1's companion game! Remember that little logic game called 0h h1? Well, we've made a challenging new puzzle game to go along with it! Meet its companion... 0h n0. 0h n0 is a lovely little logic game that follows its own three rules: - Blue dots can see others in their own row and column. - Their numbers tell how many. - Red dots block their view. It's up to you to complete the grid without ever having to guess. Simply tap a tile to make it blue or red and complete the grid. 0h n0 gives you unlimited puzzles for all four grid sizes: 5 x 5 6 x 6 7 x 7 8 x 8 And now included: 4 x 4 and 9 x 9 boards! Each puzzle can be played in perfect Zen mode without any pressure. But you can attempt to beat your personal best time in the game's time trials, unlock fun achievements and compete with friends in leaderboards. 0h n0 is free, without ads, without social network requirements, without locked features and without nag screens. 0h n0 is a little gift to you. We hope you enjoy it. 0h n0 can also be played on 0hn0.com. And if you haven't played its sibling yet, go visit 0hh1.com. ## Key features - Logic-based grid puzzles - Blue and red dot placement - Unlimited puzzles - Multiple grid sizes (4x4 to 9x9) - Zen mode - Time trials - Achievements and leaderboards ## Pricing and in-app purchases Base price: Free. **One-time purchases** | Purchase | Price | Type | | --- | --- | --- | | 0h n0 Supporter | $0.99 | one-time | ## Recent user reviews (10 of 36) All indexed reviews: https://appshunter.io/ios/app/0h-n0/id957191082/reviews.md ### 4/5 — So fun *2024-10-14, version 1.0.6* It’s great if you like sudoku or similar games, I just wish I could restart a board or pause and return to a board later. Then the game would be perfect ### 5/5 — Absolutely Obsessed *2024-05-31, version 1.0.6* It is so simple, yet so effective. It’s a great puzzler to unwind as it is just difficult enough to challenge you but not impossible. Additionally the fact that you can determine your own level of difficulty of the puzzle every time is wonderful. 10/10 have shared with so many people. ### 5/5 — Fantastic *2024-04-27, version 1.0.6* 0h n0 is easy to understand and fun to master. You can choose between a range of boards, the bigger the board, the more patterns to analyze and solve. Lower boards are great for new players to make sure they don't get overwhelmed and incrementally level-up. As they become a seasoned player they may know that each board can be completed without guessing, so the different sized boards can offer a zen like experience as they zip their way to completion. Every individual has a different baseline level of stimulation, allowing seasoned players to go back to the earlier boards and find their own zen board. My zen board is the 5x5. The competitive aspect is engaging for me personally. I compete with myself for the best times, but try to go for the endurance "boards completed" leaderboard for my zen board. I've been tracking a few active players in a spreadsheet and it's cool to see our rates vs absolute scores. The app itself is distraction free. No ads. No internet required. You can play anytime, anywhere, and fully immerse yourself into the game. The app does have some imperfections, right now there are 3 main bugs with the app, first is that you can't skip through the menu making the "impatient" achievement impossible, and the second is opening game center sometimes crashes the game. Pairing those two together can be annoying for competitive play. The other bug is that the timer gets disabled when you visit certain menus (How to play does this i think). I've also had some fun exploring potential shortcuts to save time. I've found out two major time savers which I call the blind dot rule and the related dot rule. I leave that as an exercise for the reader 😉 Overall, great game! ❤️ ### 5/5 — I love this game *2024-03-26, version 1.0.6* This is still, after quite a few years, one of my favorite “go to” (uh, “g0 t0”?) games on the iPad. I know it hasn’t been updated in ages, and I’m fine with that, but one day I hope the developer can treat us to a new version with larger puzzles. 9x9s are too easy after a few thousand of them. :) ### 5/5 — App Store Hidden Gem *2023-12-20, version 1.0.6* Quickly became my favorite puzzle game - and I’ve got a few! The replayability is glorious. Well done!! ### 5/5 — ADHD Focus aid *2023-11-30, version 1.0.6* This game has served as an ideal aid for me to pay better attention to college lectures. It has no required auditory components and requires no reading, while providing a sufficiently challenging puzzle ti prevent my mind from wandering while not being so complicated I ignore the lecture I am listening to. It has no necessary time component, so the game can be paused and resumed at any time, allowing me to take notes as necessary or otherwise engage in class as needed. Both games in the series have been incredibly helpful, and are fun in their own right. I'm thankful to the devs for creating and maintaining these titles. Now working as a professional counselor, I recommend these games to my ADHD clients who are under-stimulated in lecture settings ### 5/5 — Non-addictive app *2023-04-17, version 1.0.6* I really appreciate this app, because since deleting social media apps from my phone which sucked me in and kept me scrolling, I’ve needed a replacement app that I can open when waiting somewhere, but I can also easily close and step away from. The puzzles are the right amount of challenging, and there are no ads so it doesn’t become annoying to play. Just relaxing and comforting and interesting. Thank you! ### 5/5 — Best of the best *2023-01-27, version 1.0.6* This was one of the first games I tried on my phone. It never gets old, it is the definition of a great, engaging, entertaining, quick break. ### 5/5 — Great game *2022-09-05, version 1.0.6* Similar to “oh hi” in that it requires some basic pattern recognition, and quick thinking. Better than “oh hi” because it’s a bit more complex and requires some math skills. Great way to wake up your brain when competing against the clock. ### 1/5 — Forcing to login *2022-05-06, version 1.0.6* Horrible app, tries to force a Game Center login every time it opens. Terrible design ## Frequently asked questions about 0h n0 ### What is 0h n0? 0h n0 is a logic puzzle game that challenges you to complete grids by placing blue and red dots. Blue dots have visibility rules based on their row and column, and their numbers indicate how many they can see. Red dots block visibility. The goal is to solve the grid without any guessing. ### What are the main features of 0h n0? The game offers unlimited logic puzzles across various grid sizes, from 4x4 to 9x9. Players can enjoy a pressure-free Zen mode, compete against their best times in time trials, unlock achievements, and climb leaderboards. ### Is 0h n0 free to play? Yes, 0h n0 is completely free to play. It is offered as a gift with no ads, no social network requirements, no locked features, and no nag screens. ### What devices is 0h n0 compatible with? While specific device compatibility isn't detailed, the app is available for mobile devices. It can also be played on the web at 0hn0.com, suggesting broad accessibility. ### How do I play 0h n0? To play, you tap tiles to make them either blue or red. Blue dots follow specific visibility rules based on their row and column, and their numbers indicate how many other dots they can see. Red dots act as blockers. The objective is to fill the grid correctly according to these rules. ## Version history (last 4 releases) ### 1.0.6 — 2017-10-21 This app has been updated by Apple to display the Apple Watch app icon. Updated for iOS 11. ### 1.0.5 — 2015-10-03 0h n0 is nominated for a LOVIE AWARD! Please vote! www.peopleslovie.eu/#games-3 And you can now increase the difficulty by going into settings and disabling the hint icon. Plus, there's a progress percentage. Don't forget the recently added 9 x 9 and 4 x 4 boards with new achievements, leaderboards and themes based on our other games 0h h1 and Contranoid. Made with love and free as always! If you're a fan of 0h n0, the (optional) support purchase is an awesome way to keep us going! Cheers! ### 1.0.4 — 2015-09-22 0h n0 is nominated for a LOVIE AWARD! Please vote! www.peopleslovie.eu/#games-3 A lot is new! 9x9 and 4x4 boards are here, themes based on our other games 0h h1 and Contranoid can be found in the Settings page and new fun and functional achievements and more leaderboards are here for you! Made with love and free as always! But if you're a great fan of 0h n0, the (optional) support purchase is an awesome way to keep us going. Enjoy! ### 1.0.1 — 2015-02-11 No release notes. ## Apps similar to 0h n0 | App | Rating | Price | Category | | --- | --- | --- | --- | | [Tectonic \| Logic puzzles](https://appshunter.io/ios/app/tectonic-logic-puzzles/id1628584293) | 4.8 (4) | Free | Games | | [Star Battle Puzzle - Hoshi](https://appshunter.io/ios/app/star-battle-puzzle-hoshi/id1663477610) | 4.8 (244) | Free | Games | | [Sudoku - The Clean One](https://appshunter.io/ios/app/sudoku-the-clean-one/id1442274281) | 4.6 (55) | Free | Games | | [Hashi: Bridges](https://appshunter.io/ios/app/hashi-bridges/id567583852) | 4.9 (961) | Free | Games | | [Zuzu · Binary Puzzle Game](https://appshunter.io/ios/app/zuzu-binary-puzzle-game/id1050532023) | 4.4 (64) | Free | Games | | [LogiBrain Tents and Trees](https://appshunter.io/ios/app/logibrain-tents-and-trees/id1506363379) | 4.3 (9) | Free | Games | ## More apps by Q42 B.V. - [Quento](https://appshunter.io/ios/app/quento/id583954698) - [Flippy Bit & the Hexadecimals](https://appshunter.io/ios/app/flippy-bit-and-the-hexadecimals/id853100169) - [0h h1](https://appshunter.io/ios/app/0h-h1/id936504196) - [Contranoid](https://appshunter.io/ios/app/contranoid/id1027717534) - [Hue Clips](https://appshunter.io/ios/app/hue-clips/id1537070371) All apps by Q42 B.V.: https://appshunter.io/developer/385525157 ## Related topics [ohhi](https://appshunter.io/ios/topics/ohhi) · [ohno](https://appshunter.io/ios/topics/ohno) --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-05.*