Entitled The Phantom, this 99¢ expansion adds “a ghostly-transparent meeple (i.e. game piece) that can be played in addition to a regular one during the players turn”.
Originally released in 2000, the physical board game has seen quite a number of expansions over the past 14 years. TheCodingMonkeys, whose own iOS version is about to turn four years old next week, have done a rather nice job at rolling out some of these expansions digitally as inexpensive in app purchases, keeping the game fresh. It is awesome to see the game continue to be expanded and supported after so many years.
According to the folks over at Board Game Geek, this expansion first appeared in the physical game back in 2011 and today it makes its way to the digital version as well.