GridDay — Logic puzzles, refined

Five games, one app

Number-logic classics, all free to play.

• Sudoku — Classic number placement

  9×9 grid · rows, columns, and 3×3 boxes

• Killer Sudoku — Sum cages & smarter challenges

  9×9 grid with sum cages · arithmetic meets logic

• Kakuro — Cross-sum logic puzzles

  Cross-sum logic · fill white cells so each run hits its target

• Calcudoku — Latin square with cage operations

  Latin square with cage operations · +, −, ×, ÷

• Futoshiki — 5x5 Latin square with inequalities

  5×5 Latin square with inequality clues between cells

Built for focus

A calm, refined take on logic puzzles.

Five games in one

Sudoku, Killer Sudoku, Kakuro, Calcudoku, and Futoshiki — one polished app.

A new daily challenge

Every day brings a fresh daily for each game, at a difficulty that rotates through the week.

Your stats, your device

Best times, streaks, and achievements tracked locally. No account needed.

Hints that teach

Stuck? A smart hint shows the technique and the reasoning — not just the answer.