# 0h h1

> Logic puzzle game with tile-based challenges and unlimited grids. (iPhone/iPad app by Q42 B.V..)

- Source: https://appshunter.io/ios/app/0h-h1/id936504196 (this page in markdown: same URL + `.md`)
- Developer: [Q42 B.V.](https://appshunter.io/developer/385525157)
- Category: Games, Education, Board, Puzzle
- Price: Free with in-app purchases
- Rating: 4.70/5 from 299 App Store ratings · 74 written reviews indexed
- Age rating: 4+
- Requires: iOS 8.0 · 3 MB
- Languages: American English
- Released: 2014-11-12
- Data updated: 2026-07-06
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/0h-h1/id936504196/reviews.md

## What is 0h h1?

0h h1 is a little logic game that follows three simple rules:

- Three red tiles or three blue tiles next to each other in a row or column isn't allowed
- A full row or column must have as many blue tiles as it has red ones.
- No two rows are the same. No two columns either.

Simply tap a tile to make it red or blue and complete the grid.
0h h1 gives you unlimited puzzles for all four grid sizes: 

4 x 4
6 x 6
8 x 8
10 x 10

0h h1 is free, without ads, without social network requirements, without locked features and without nag screens. 0h h1 is a little gift to you. We hope you enjoy it.

0h h1 can also be played on 0hh1.com.

## Key features

- Tile-based logic puzzles
- Three simple rules
- Unlimited puzzles
- Four grid sizes (4x4 to 10x10)
- Tap to change tile color

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| 0h h1 Supporter | $0.99 | one-time |


## What do users think of 0h h1?

Overall sentiment: positive

**Pros**

- ✨ No ads or in-app purchases
- 🧠 Challenging yet simple gameplay
- 💡 Helpful hints provided
- 🧠 Great for focus and ADHD
- 👍 Long-term player satisfaction
- 💯 Minimalist and appealing design
- 🚀 Smooth gameplay
- 💡 Unique and genius concept
- 😌 Relaxing and decompressing
- 🆓 Free to play
- 💡 Supports audiobooks well
- 💡 Low storage usage
- 💡 Visually appealing
- 💡 No required sound components
- 💡 No reading required
- 💡 Can be paused and resumed
- 💡 No time component
- 💡 Ideal for college lectures
- 💡 Recommended for ADHD clients
- 💡 Addictive without being time-consuming
- 💡 No guessing involved
- 💡 Never frustrating
- 💡 Minimalist design
- 💡 Logical brain-picking
- 💡 Simple yet deep gameplay
- 💡 Elegant and entertaining
- 💡 Quick and fun bursts
- 💡 Easy to learn
- 💡 Tricky to master
- 💡 Great for short breaks
- 💡 Deceptively simple
- 💡 No gamification elements
- 💡 Great logic puzzle
- 💡 No gimmicks
- 💡 Good for spare moments
- 💡 Beautiful aesthetics
- 💡 Well-built code

**Cons**

- ⚠️ Clipboard access prompt
- 🐛 Progress sometimes lost on closing app
- 🐛 Leaderboard scores appear impossible (negative times)
- 🐛 Hints sometimes incorrect or unhelpful
- 🐛 Start game over option missing
- 🐛 Highlight and erase incorrect cells missing
- 🐛 Start time too long for quick play
- 🐛 Error display not reliable after update
- 🐛 Difficulty can become too easy over time
- 🐛 No sound effects
- 🐛 No background soundtrack
- 🐛 No iCloud syncing for scores
- 🐛 No leaderboards
- 🐛 No timers
- 🐛 No penalty for hints
- 🐛 Difficulty could be increased
- 🐛 No paid version for support
- 🐛 No new levels
- 🐛 Some find it too easy/mechanical
- 🐛 Needs iPad for larger grids (big fingers)

**Commonly reported bugs**

- Progress forfeited when closing app
- Randomly asks permission to paste from clipboard
- Leaderboard scores with negative times
- Hints sometimes incorrect or unhelpful
- Error display not reliable after update
- Occasional crashes (implied by 'buggy')

**Most requested features**

- Continue game progress after closing app
- In-game stats (games played, best times, scores)
- Option to start game over
- Option to highlight and erase incorrect cells
- Customizable color palettes
- iCloud syncing of scores
- More difficulty settings or games
- Timed version for scoring
- Holiday themes
- Sound effects for clicks
- Background soundtrack
- Bigger maps/grids (e.g., 12x12)
- Integration with Game Center

## Recent user reviews (10 of 74)

All indexed reviews: https://appshunter.io/ios/app/0h-h1/id936504196/reviews.md

### 5/5 — Simple and Fun

*2025-12-29, version 1.3.5*

Honestly my primary praise is that there are no ads, in app purchases, energy, or anything like that. It’s just a simple puzzle game but it’s still challenging at the same time

### 5/5 — super fun and challenging

*2025-08-16, version 1.3.5*

I love that it gives you hints when you get stuck. Easy to learn yet challenging to master. Great little brain tickler and alternative to mindless scrolling.

### 5/5 — Try it

*2025-04-30, version 1.3.5*

So satisfying, had this game for many years now. Love it

### 5/5 — Great game!

*2024-12-28, version 1.3.5*

I am totally hooked to this app! Focusing is hard for me and this helps me a lot!

### 5/5 — Objetivo e direto

*2024-09-22, version 1.3.5*

Amo

### 5/5 — Simple & Clever

*2024-07-28, version 1.3.5*

Awesome

### 5/5 — Great game

*2024-07-25, version 1.3.5*

Awesome game, super fun and challenging. For anyone complaining about the paste from clipboard feature. The game hasn’t been updated in a while and when Apple introduced that feature it hasn’t been removed from this game. If you don’t actively have something in your clipboard it won’t ask. Also if it does ask you say no and it won’t actually read that data.

### 1/5 — Security

*2024-04-25, version 1.3.5*

It prompted me to allow paste or not from my laptop.  No thank you .

### 5/5 — Favorite Phone Game

*2024-01-25, version 1.3.5*

As others have said, this game does wonders for ADHD. Its also the only game that I consistently play for years when others I usually get bored of really quickly. Only thing that even remotely bothers me about it is that it likes to randomly ask permission to paste things when I go from one app to this one? Like, it randomly pops up the “Allow paste” thing for some reason

### 5/5 — ADHD focus aid

*2023-11-30, version 1.3.5*

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

## Frequently asked questions about 0h h1

### What is 0h h1?

0h h1 is a logic puzzle game where you fill a grid with red and blue tiles. The game follows three core rules: no three same-colored tiles in a row or column, an equal number of red and blue tiles in each row and column, and no duplicate rows or columns.

### What are the key features of 0h h1?

The app offers unlimited puzzles across four grid sizes (4x4, 6x6, 8x8, and 10x10). Players simply tap tiles to change their color (red or blue) to complete the grid according to the game's rules.

### Is 0h h1 free to play?

Yes, 0h h1 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 h1 compatible with?

While the description doesn't specify exact operating systems, it implies mobile compatibility. The game can also be played on the web at 0hh1.com, suggesting broad accessibility.

### What are common use cases for 0h h1?

This app is ideal for quick brain training sessions, passing time during commutes, or engaging in a mentally stimulating challenge. Its simple rules and unlimited puzzles make it suitable for both casual play and dedicated puzzle enthusiasts.

## Version history (last 5 releases)

### 1.3.5 — 2017-10-21

This app has been updated by Apple to display the Apple Watch app icon.

Updated for iOS11.

### 1.3.4 — 2015-09-30

We're nominated for a Lovie Award!
And we've got gifts for you!

There's a present waiting for you in the size-selection screen. Fans of 0h h1 will love it :)

And there's more. You can apply visual themes to 0h h1 and make it look like our other games 0h n0 or silent-film-era Contranoid.

Plus, more achievements, leaderboards and hardcore mode by disabling the hint icon. 

If you want to keep us going, treat yourself to one of our other games or support us through a (100% optional) in-app purchase.

Have fun!

### 1.2.1 — 2015-02-28

Compete with friends in many Leaderboards and unlock fun Achievements!

### 1.1.0 — 2014-11-26

You can now continue a previous unfinished game.
You can also toggle the visibility of locks on all fixed tiles simply by tapping one of them.
And yes - subtle twitter and facebook buttons were added ;) Although non-intrusive and only when you've completed a game so you can opt to brag about it.
Oh, and the undo icon is now a bit more obvious that it is undo.

If you like 0h h1 it would mean a lot to us if you could take a few seconds to leave a review. We read them all because your compliments make our day even more worthwhile! 

Thanks!

### 1.0.1 — 2014-11-14

Added a rules sheet in the gameplay menu.
When a game ends with errors, the wrong tiles no longer light up but the hint system will indicate what rules are broken.

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## 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 n0](https://appshunter.io/ios/app/0h-n0/id957191082)
- [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) · [b42](https://appshunter.io/ios/topics/b42)

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*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 2026-07-06.*