A red ball moves along trails, which are shown on tiles of different patterns. The tiles can be slid either horizontally or vertically. The idea is to form a rail for the ball that doesn’t end into an edge.
Sidenote: At the point of posting this program has been marked as beeing freely available without costs. As this program is hosted with the AppStore the status might change. Authors like to publish their programs for free for promotion purpose and then make it commercial. Also it could happen that the author decides to take the program down.