Leadlight: Math Logic Puzzle

Fill the stained-glass window with digits, and watch the light pour through.

Leadlight is a calm arithmetic logic puzzle. Every row and every column holds each digit once. Thick lead lines split the window into cages, and the number in a cage's corner tells you how its digits combine: 12+ adds up to 12, 24× multiplies to 24, 2− is a difference, 3÷ a quotient. Find the only digits that fit, and when the window is complete, light passes through it pane by pane.

• 280 windows, each with exactly one solution you can reach by logic – never by guessing
• Four difficulties: Easy 4×4 and 5×5 with sums and differences, Medium and Hard up to 7×7 with all four operations, and Expert, where the operations are hidden and working them out is part of the puzzle
• Hints that teach: first where to look, then why, and only then the move
• Notes with auto-clear, unlimited undo, live warnings when a digit breaks a rule
• Every solved window gets its own name
• Glass taps and chimes, a short tutorial, best times per level
• No ads, no subscriptions, no account

All 40 Easy windows and the first 10 of Medium, Hard and Expert are free. The rest come in one-time packs of 35 windows, or all at once.