When's the last time you played a good game of Tic Tac Toe? I've seen numerous versions of it.
Align Puzzle - 3 in a Row comes from Adefemi Adeyemi. (interesting name!).
Play against a friend or against the computer. You place your 3 stones, the computer does its 3 stones. After that, you may slide one of your stones to an empty square by travelling along one of the lines.
Look at the second image. See the blue stone in the bottom row? It's trapped and cannot move. The blue stone in the upper right has only 1 possible move. While the blue stone in the middle has 2 options.
Align Puzzle 3 in a Row seems to combine Tic Tac Toe with Nine Men's Morris, which is another very old game that's actually very sophisticated. Do check that game out. Some versions of that have diagonal lines drawn at the corners, others do not.