Adder Frame

Adder Frame is a crossword made of digits. Instead of words, each run of white cells has a sum written on the clue cell beside it, and the digits in that run have to add up to exactly that — using one through nine, never the same digit twice inside one run.

The short runs are where you start. A run of two adding to 3 can only be 1 and 2; one adding to 17 can only be 8 and 9. From there the crossing runs do the rest.

Each grid comes with a few starter digits in a different colour. They are not decoration: a kakuro grid of this size almost always has several valid fillings on its own, and those starter digits are what cut it down to exactly one. They were added one at a time until the answer was unique, then every one that turned out to be unnecessary was taken back out.

Tap a white cell to select it, pick a digit from the strip below, tap the same digit again to clear it. A repeat inside a run, or a finished run that does not add up, turns red immediately.

Ten grids, from twenty white cells up to fifty-seven. Each grid is fixed to its level.

Offline, no accounts, no forced ads, nothing to buy.

Features:
- Every run adds up to its clue, with no repeated digit
- A minimal set of starter digits, so each grid has one answer
- Mistakes turn red as soon as they happen
- Ten grids, twenty cells up to fifty-seven
- Each grid fixed to its level
- Works fully offline