I'm creating a game, I have a grid and a ball, and I want that the ball follow the position of the grid, please see the image.
How can I do it ?
You should add the ball as a child node of the grid. For example:
grid.addChild(ball)
For more information see Creating the Node Tree in the documentation: https://developer.apple.com/library/ios/documentation/GraphicsAnimation/Conceptual/SpriteKit_PG/Nodes/Nodes.html