Chemin

Chemin has been listed as one of The Very Best Puzzle Apps of 2013 (http://gottasolveit.blogspot.com/2013/12/the-very-best-puzzle-apps-of-2013.html)

Chemin is a puzzle game whose goal is to place numbered pieces in a board in a continuous ordered sequence taking into account the pieces already in the board.
The only rule is that a piece must be placed up, down, right or left of the previous one in order to form a continuous sequence to fill the board.

Features:
7 levels with increasing difficulty
175 puzzles (25 puzzles per level)
Boards with 4x4, 5x5, 6x6, and 7x7 tiles