Nudoku

This is a Sudoku that can be played with several display variants:
- The digits 1-9, now also with some other writing systems: arabic variants, n´ko, chinese, roman
- A selection of standard Emojis,
- Hand painted drawings,
- AI generated images,
- Colors
- Picture sets downloadable from the shop

The game can be played either in prefilled mode, where the setup guarantees that there is a single solution for the puzzle, or in free filling mode with an empty grid. In free filling mode, after each placement the board is checked if a solution is possible. When no solution is possible a red frame will be shown around the board. If a single solution is found, there will be a green frame and the "play" button on the right will be enabled. Press this button to start the timer for the "custom" high score category and to enter normal game mode for solving the game.

For very small screens, a setting allows for a two step selection when tapping one of the blocks of 9 cells first before changing the value itself. In this case, when you tap on the blocks, the cell block will magnify for an easier selection of the cell within the block.
There also is a setting for the difficulty level. The higher the setting, the harder the app tries to remove more values when setting up the board, while still guaranteeing a single solution.

This free variant lacks the options to save games that are available in Nudoku+, which can be added through in-app buy,

There is also a chinese character training mode available in the shop that uses the charcacters from the Qianziwen 1000 characters primer.

Known issues:
- Very small screens on older Android Nougat models may have some dialogs looking crowded.
- The block selection mode only works when tapping on one of the modifiable cells, hitting one of the fixed cells does not magnify the block. Will be fixed in the next version.
- On some devices between Android Oreo and Android Snow Cone there is a stability problem with the current version that is difficult to reproduce