From the release:
Legionnaire Games have released a free demo of our upcoming Grand Tactical WWII tabletop wargaming rules, Weltkrieg. This demo includes the complete game's basic rules, plus all of the unit data, force organization charts, and game markers to play the enclosed scenario (Prokhorovka).
Written primarily for 6mm figures, the game can easily accommodate figure scales ranging from 2mm to 15mm.
The complete book, which focuses on German and Soviet forces on the Eastern Front, will be available by the end of August. Additional expansion will cover armies of other nations on the Eastern Front, and ( the Western, Desert, and Pacific theaters of war.