Nonogrids (BrainBashers)

Nonogrids follows the rules of the puzzle known as nonograms, griddlers or paint by numbers. Beside each row and above each column is a short list of numbers. Each number is the length of a run of consecutive filled squares in that line, and the runs appear in the order listed, with at least one empty square between them. A clue of 3 1 2 means a run of three, then one, then two. Working back and forth between rows and columns, you fill in the blocks until every line matches.

Kevin Stone's BrainBashers posts five grids a day that grow with the difficulty: 5x5 and 10x10 at Easy, 15x15 at Medium, and 20x20 and 25x25 at Hard, with a 30x30 weekly special. The play page has check, answer, print and restart buttons, an option to show mistakes, an optional clock and an alternative border style that helps on big grids. A help page walks through the method.

The set changes at midnight GMT or at the time zone you set, and the date list keeps the last four weeks of grids. Random easy, medium and hard buttons on every puzzle page give extra grids beyond the daily set. You click a square to fill it and double-click to mark it empty. No adverts, no account.

The grids are drawn at a fixed size, so on a phone the 10x10 fits the screen while the 15x15 and larger run past the right edge and need scrolling.

It suits nonogram fans who want a daily set that runs from a one-minute warm-up to a long 25x25.