), left one for redo (
).Put ysudoku.apk file on your device and install. It does not require any permission.
For now only internally generated puzzles could be played.
Select place (by tapping on it) and then tap on the digit from digit row to put digit there.
Double tapping on digit (from digit row) will put a green mark in empty cell.
Long press on digit (from digit row) will put a red mark in empty cell.
Color does not have any special meaning for the game it's just a way to put marks. Usually green marks are used to mark possible positions, while red ones to mark not possible positions.
There are 2 U-turn arrow icons - right one is for undo (), left one for redo ().
Long press on this icons will do: full undo (undo all moves) / full redo (redo all moves, if redo buffer is not empty)
Tap on middle icon (
) and select puzzle level you want to play.
There is icon with cross on it (
).
When active (icon becomes red with white cross - 
) it will notify you on errors. So putting a digit which conflicts with other digits will be marked red.
Long press on that icon will show even more cases where errors are possible (icon will become red with yellow cross - 
).
Will mark row/col/square red if in that row/col/square it is not possible to have some of the digits.
Clicking on icon with question mark (
) will show marks with possible digits.
Long press on it will auto play those which has just single possible mark in a cell.
Double tap on it will auto play all digits which program can calculate.
Warning: if you select auto play then usually all levels (except crazy) will be auto solved (so it is not interesting).