In Kriegsspiel chess variation you can not see your opponent's pieces. In ChessFog you always see the opposing King and any opposing pieces under attack. ChessFog also let's you assemble your traditional set of chess pieces anywhere in the first 3 rows of your side of the board and when playing another human player you can opt for single or multiple moves per turn. In multiple move turns you can only move a piece once. There is also an option to play the computer AI bot called Plato. The app has a page with the full set of rules.
ChessFog is a chess variation based on Kriegsspiel with modern improvements.