I have found a puzzle app called Snakeword. It is just like a crossword but every time you put in an answer you must change direction when you enter a vowel. Words have to reach from one numbered square to the next and the last letter of each word forms the first letter of the next. It is really cool and free!! Download from the apple app store of follow the link on www.snakeword.com - I love it and so do my friends, if you like crosswords then it;s definitely worth a look!