If to guess one variant from three, this is luck. Moreover, if to guess two of three, this is fantastic luck. So, what if one can guess always? And not one variant from three, but one of hundred. Not possible? You do not believe... Right you are. Mortal have not this gift. Only sphinxes, which penetrated with their beams both alive and lifeless, have had such skill. Therefore, any secret could not hide from them. We do not possess all their knowledge too, but one their skill in guessing the thought numbers has given in to our solution. So try it. May be you will reveal this secret too, or may be not. However, your friends will really consider you as a magician and wizard.
https://market.android.com/details?id=com.mobilegames.xsphinx
https://market.android.com/details?id=com.mobilegames.xsphinx