Ursograma is a nonogram: the numbers on each row and column tell you which cells to fill, and at the end a picture appears. No guessing needed: every ursograma can be solved by logic alone, one line at a time.
The rules
Each number is a group of consecutive filled cells. The numbers of a row are read from left to right, and those of a column from top to bottom, in the same order as the groups.
2 1 3 | ■■×■××■■■×
2 1 3: a group of two, then one of one, then one of three. The gap between groups can be one cell or more.
Between two groups of the same colour there is at least one empty cell.
Before the first group and after the last there may be empty cells, or none.
A 0 means the whole line stays empty.
Colour ursogramas
In some ursogramas the numbers come in colours, and each group is filled in the colour of its number. The gap rule changes in one detail: two groups of different colours can sit right next to each other.
2 2 | ···· → ■■■■
A red 2 and a blue 2 in four cells: they only fit side by side, and the line is solved.
Filling and marking
Tap a cell to fill it with the mode chosen below the grid: Fill (or one of the colours) or X.
Drag to fill several cells at once. The drag stays locked to the row or column where it started, and doesn't change cells you have already decided.
Starting on a cell that already has the mode's value clears it: that is how you undo a whole drag.
Zoom: on a phone, spread two fingers to zoom in and drag with two fingers to move the grid; one finger still fills. There is also the magnifying glass button, and on a computer Ctrl (or ⌘) with the mouse wheel. The numbers always stay in view, pinned to the edges.
On a keyboard: arrow keys to move, Space to fill, X to mark, Backspace to clear and Ctrl+Z to undo.
The first techniques
You solve one line at a time: what a row decides helps the columns that cross it, and vice versa. These four ideas are enough to get started.
Overlap. Try pushing the whole group to the left, then to the right. The cells filled in both positions are definitely filled. It works with several numbers on the same line too: it is all in Overlap.
7 | ·········· → ···■■■■···
A 7 in ten cells: pushed left it runs from the 1st to the 7th, pushed right from the 4th to the 10th. The four in the middle can be filled now.
From the edges. A filled cell next to the edge must be the start of the first group. The whole group is filled, and the cell after it stays empty. It also works near the edge and after closing a group: see From the edges.
3 | ■······· → ■■■×××××
The first cell is filled and the number is 3: fill the first three, and the rest of the line stays empty.
Gaps that are too small. A gap between Xs (or between an X and the edge) where no group fits stays empty.
3 | ··×······· → ×××·······
The 3 doesn't fit in the two cells before the X, so they stay empty.
Crossing. Every cell belongs to a row and a column. When a row decides a cell, go back to its column: often that is the very cell it needed to move forward. That is how an ursograma gets solved, in a back-and-forth between rows and columns.
Help
The Hint button shows a row or column where there is something to decide and, if you ask for more, what it is. If you have a wrong cell, it warns you about that first.
Show mistakes (in the ⋮ menu) flags wrong cells as you play.
With help, your time doesn't count in the statistics. Fading the numbers of a complete line and automatic Xs don't count as help: they reveal nothing you can't already see.