Press kit.
Everything on this page may be quoted. For anything else: support@keitgen.de.
Fact sheet
- Name
- Sudoku Purist
- One-liner
- Sudoku, just like it used to be in the daily paper — one puzzle a day, the same one for the whole world.
- Model
- The daily puzzle is free. A single one-time purchase unlocks unlimited puzzles. No subscription. No ads anywhere, in any tier.
- Platform
- iOS — App Store
- Launch
- 2026
- Developer
- Joseph Keitgen — solo, Germany, building sudoku apps since 2011.
- Contact
- support@keitgen.de · sudokupurist.app
The story
“I updated my app and scared some of my users away.”
In early 2026, Joseph Keitgen shipped a major redesign of Sudoku by Joseph, the sudoku app he has built alone since 2011. Most players liked it. A steady trickle of longtime users did not — their emails all said some version of “I just want to solve a puzzle. Why is all this stuff here?”
He began writing back to defend the features, and halfway through one of those emails realized the users were right. Instead of arguing, he built them a second app with everything removed.
Sudoku Purist is the result: one puzzle a day, the same one for the whole world, black and white like the newspaper. The free tier has no ads either; a single one-time purchase — no subscription — unlocks unlimited puzzles. It is a tribute to the players who asked for less.
The feature list, in full
No ads. No hints. No timer.
No statistics. No streaks. No color.
Assets
Logo: download SVG. Use it on paper or on black; do not recolor it.
1024 px PNG ]
per device —
at launch ]
recording —
at launch ]
Short answers
Why one per day? The newspaper never gave you two.
Why no hints? The newspaper could not offer any either.
Why is it the same puzzle worldwide? So you can talk about it.
Relationship to Sudoku by Joseph? Same developer, opposite philosophy. The main app has variants, statistics and themes; Purist is for the players who asked for less.