No three identical in a line
Binary Puzzle does not allow three 0s or three 1s in a row, and the same for a column. Two identical symbols next to each other force the other symbol on each open side.
An empty cell between two 0s is a 1. An empty cell between two 1s is a 0. That sandwich is a forced move. Mark it as soon as you see it.
The rule is about three in a straight line, not about a diagonal. Scan each row and each column. On 6×6 and 8×8 the same scan works.
Together with equal 0s and 1s, this solves the easiest boards. Play Binary Puzzle. How to play Binary Puzzle.