Number Snake Ultra (com.rrTenz.NUmber_Snake) on Google Play
Number Snake is a fun number game where you fill in boxes with sequential numbers until you have completed the puzzle. Every adjacent box has to have a number that is one greater or one less than a box next to it (no diagonals). Thus making an unbroken path of numbers from 1 to the maximum number in a puzzle (e.g. from 1 to 49 on a 7x7 puzzle). It is similar to the game Numbrix from Parade magazine. These are the key differences: (1) Customizable puzzle sizes (5x5 to 20x20) (2) Puzzles with multiple solutions (3) Infinite puzzles available (4) Customizable puzzles.