Privacy Friendly Sudoku App

The android application Privacy Friendly Sudoku is a logic puzzle game. The goal is to fill the complete board with numbers. Every number may only occur once in every column, row and subsection. It belongs to the group of the Privacy Friendly Apps.

A level generator is built into the app, which automatically generates new levels in the background while the game is being played. This is done to minimize loading times. A generated game is always uniquely solvable.

Privacy Friendly Sudoku has three game modes:

  1. a 6x6 game field with 2x3 subsections
  2. a 9x9 game field with 3x3 subsections
  3. a 12x12 game field with 3x4 subsections

For each game mode there are four different difficulty levels, that are not measured by the number of preset values but rather by the solving strategies needed to solve the game. The generator always tries to provide a game that has the minimum amount of preset values needed to solve the game. Additionally, users can create their own custom sudokus of arbitrary difficulty for each of the three game modes. These sudokus have to be verified as uniquely solvable before they can be played.

  1. Easy
  2. Morderate
    • Singles
    • Hidden Singles
  3. Hard
    • Naked Pairs/ Triples
    • Hidden Pairs/ Triples
    • Pointing Pairs/ Triples
    • Box Line Reduction
  4. Challenge
    • The generator checks for the above mentioned strategies. If the generator has to take a guess, the level is automatically classified as hard. A human player has many more strategies available, with which these puzzles are solvable as well.


A detailed description of the available solving strategies can be found here.

A maximum of ten games can be saved and continued at any time.

A list with the best times is available, that saves the best times for each game mode and difficulty. Custom sudokus are not included in this list.

Furthermore there is a help function concerning the selected field. If you use it, you will not be able to achieve a best time in the current game anymore.

Sudokus can be shared with other users by using the available import and export functions. Another community feature is the 'daily sudoku', which is newly generated each day and the same for every user of the app. The difficulty of the sudoku is chosen at random, however the 'challenge' difficulty is less likely to be picked than the other difficulties.

The app can be used in both light and dark mode.

Our Privacy Friendly App differs from other applications with respect to two aspects:

  1. No permissions
    The Privacy Friendly Sudoku App does not use any permissions.
  2. No advertisement
    Many other free apps in the Google Play Store dazzle annoying advertising which also shortens battery life.


Download the App 

We offer several ways to download the app:

  • Play Store (Feel free to provide feedback, see contact. We would be pleased to receive a positive rating if you like the app )
  • F-Droid Store (The F-Droid Store is an open source software store where you can download the APK-file of the app.).
  • If you are interested in the development of apps or the source code, you can find it at GitHub.