Sum Grid: Killer Sudoku

Killer Sudoku without guessing. Every puzzle has exactly one solution, checked to be solvable by logic alone before it reaches you. No ad ever interrupts a puzzle. The only ad you don't ask for comes after you finish. Climb to the Summit: every solved level lays a block in one of ten monuments. Sum Grid is the classic Killer Sudoku: Sudoku rules plus cages whose digits must add up to their sum. Every board is checked for a unique solution, then solved end to end by the same logic engine that powers the hint button. When you are stuck, there is always a next logical step. WHY IT IS DIFFERENT • Verified, no guessing — one solution per puzzle, reachable by logic alone • Cages you can read — soft tinted trays with the sum on a tab, clearly apart from the box lines. Prefer the newspaper look? Classic lines are one switch away • Hints that explain — the next step names the technique (cage combinations, the 45 rule, innies and outies), marks the cells and says why, instead of just filling in a digit • Combination helper — select a cage and see every digit set for its size and sum, complete and never cut off • Notes like on paper — pencil in candidates or fill them all in one tap, with undo and redo • Checks your way — a quiet "there is a mistake" or the cells involved; rule breaks only if you want them • A calm board — no coins, no lives. Every helper is optional; Paper mode turns them all off A JOURNEY WITH A GOAL Start gently: four 6×6 levels, the first two with some digits already given, then your first 9×9 boards, again with a few given digits. From there the climb gets harder band by band. Every solved level lays a block, three stars make it gold, and each stretch builds a monument: the Cairn, the Stair, the Gate, the Tower, the Lighthouse, the Bridge, the Citadel, the Temple, the Pagoda and the Summit. Level 100 completes the Summit, and the puzzles go on beyond it. MORE WAYS TO PLAY • Classic — Beginner 6×6, then 9×9 from Easy to Expert; the puzzles never run out • Daily — the same puzzle for everyone, with a streak and a calendar archive • Techniques — nine techniques in short lessons with practice, from unique combinations and the 45 rule to What if A LOOK THAT HELPS Valley: warm sand, terracotta clay and soft cage colours. When a cage adds up, its tray lifts and the sum tab gets a check. Moonstone is the calm blue night look; Automatic follows your device. Cage edges and notes stay easy to read in both. PROGRESS THAT STAYS XP and levels, a best time for every size and band, solve counts and averages, Game Center leaderboards and achievements. Every move is saved; Continue takes you back to the puzzle you left. FAIR ABOUT ADS Sum Grid is free and funded by ads, on fair terms: • A full-screen ad only after a finished puzzle, when you tap Next puzzle or Home — never during one • The first two checks of every puzzle are free; hints and further checks come with a short video, only if you ask for one • One purchase removes every ad for good, including those videos. No subscription Plays offline. No account. Eight languages.