must be one
Make everything become one
Only for iPhone
Free
iPhone
must be one is a number puzzle built on a single rule — the one in its name.
A grid of numbers. Four operators. Combine neighboring tiles with arithmetic and collapse the whole board down to a single 1. That's the entire game: all becomes one.
It reads as obvious for about three moves. Then it doesn't.
- One rule, no filler — no twenty-minute tutorial, no menus to dig through. You understand it in seconds and spend the rest of your time actually thinking.
- Always solvable — every stage is generated so that a solution is guaranteed to exist before you ever see it. If you're stuck, that's on you, not the board.
- A climb that keeps widening — early stages stay in single digits; later ones open the range up and the arithmetic gets meaner.
- Free, and quick to pick up. One stage on the train; look up an hour later.
From office-canard — a one-person studio making small, system-first games. If this one gets its hooks in, there are more small games where it came from.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
Game Center support added.
Various stability improvements.
The developer, office-canard games, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Used to Track You
The following data may be used to track you across apps and websites owned by other companies:
- Identifiers
- Usage Data
Data Linked to You
The following data may be collected and linked to your identity:
- Identifiers
- Usage Data
- Diagnostics
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Diagnostics
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- FIT NEST, K.K.
- Size
- 6.6 MB
- Category
- Puzzle
- Compatibility
Requires iOS 15.6 or later.
- iPhone
Requires iOS 15.6 or later. - iPod touch
Requires iOS 15.6 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Contains
Advertising
- Copyright
- © 2026 FIT NEST, K.K.
