Sudoku Exchange

Two ways to play, in one calm, offline puzzle app. CLASSIC SUDOKU Easy, Medium and Hard puzzles, each with exactly one solution. Number-first entry is the default: pick a number, then tap squares to place it. Prefer the other way round? Square-first is a setting. Pencil marks let you note candidates, Fill notes works out what is still allowed, and writing a number tidies the notes around it. Undo has your back. SUDOKU EXCHANGE A different way in. The board starts completely full, and every row is already correct. Swap two numbers within a row to repair the columns and boxes. Any valid Sudoku wins. Gold, silver and bronze medals reward an efficient repair. A DAILY PUZZLE, AND A STREAK WORTH KEEPING Everyone gets the same daily Exchange puzzle. Solve it to build a run of consecutive days. Every seventh solved day earns a rest day, held two at a time, so one busy day does not erase weeks…