GHOST for Mac

From Custom Solutions of Maryland:

GHOST is a computer version of the age-old game in which you try to add a letter without making a word; one and two letter words do not count. If you make a word, you get a letter (the first letter is "G"). When you have all five letters ("GHOST"), you lose. In this version, you play against the computer. If the computer cannot add a letter without making a word, it takes a letter immediately. You can "challenge" the computer by clicking on the "I Challenge" button. The computer's word will be displayed and you will take a letter. If you catch the computer bluffing, the computer will take a letter. The GHOST word set includes over 80,000 American English word and you can maintain your own word set. It is surprising how many words there are that are not commonly used.