Pure Sudoku!

This is a pure, clean Sudoku app, crafted with care by a Sudoku lover for fellow enthusiasts.

It’s mainly for casual games at the moment, but it still assumes you already know the basic concepts and rules of Sudoku:

- A horizontal line of 9 cells is called a “row”, a vertical line of 9 cells is a “column”, and each 3×3 group of cells is a “box”.

- Digits 1–9 must be placed in all cells, with no duplicates within any row, column, or box.

- At any moment, multiple digits might be possible for a single cell. You can add “pencil marks” (small digits) to help you infer the final answer by checking the pencil marks in surrounding cells.

For experienced users: this app currently supports techniques up to size-3 subsets (naked/hidden triples). More advanced techniques are actively under development, and future versions will include a “Professional Mode” designed for advanced players.

Key Features:

• Dual Keypads

- Keypads for entering answer digits and pencil marks are shown on the screen at the same time.

- This helps prevent mistakes caused by forgetting to switch between answer mode and pencil-mark mode.

• Auto-fill Pencil Marks

- By tapping the wand icon, you can fill pencil marks for all empty cells with one click.

- It only fills empty cells — if you’ve removed some pencil marks using a technique, don’t worry, it won’t overwrite your work.

- It’s also handy when your pencil marks get messy: just clear the cell and tap the wand again.

• Cross-hatching

- When you tap a cell, a set of crossing lines appears, shading out all rows, columns, and boxes affected by that digit. This makes it easier to spot the available cells for the selected digit.

- It’s useful in easy games, and at the beginning and near the end of puzzles of any difficulty.

• Highlight Digits

- When you tap a cell that contains a digit, all other cells with the same digit — including pencil marks — will be highlighted.

- This is useful for spotting “single-digit patterns” such as hidden singles and locked candidates.

• Progressive Hints

- All hints are shown step by step. They don’t just give you the solution — they also show you why it works.

- Except for simple “single” techniques, most hints follow an “observation → reasoning → conclusion” structure.

- To close the hint pad without applying it, just tap anywhere on the game board.

• Auto Pause

- When you leave the app for any reason, it will automatically enter pause mode and stop the timer.

- You can also manually pause a game from the game menu, but you don’t really need to — want to pause? Just jump back to your home screen or turn off your display.

- Opening a hint won’t pause the game, and you can’t pause while a hint is open anyway :D the time you spend on hints still counts toward your final time.

• Themes

- Supports both light and dark themes, as well as an “Auto” mode to follow the system appearance.

• Optional Timer and Mistake Count

- The timer and mistake count can be shown above the board, and you can toggle them anytime in Settings.

- They are completely optional and are just for your reference — there are no penalties for taking too long or making too many mistakes.

• Statistics for a Single Game

- You can toggle the simple statistics in Settings; they will show your time used, mistake count, and hint usage after you solve a puzzle.

- These are completely optional and just for your reference.

- They are separate from the timer and mistake count shown above the board — you can hide them during the game and still get the statistics afterward, or vice versa.