One of the issue with playing with supplements is the sheer number you sometimes need to carry. The advantage of an iPad version is that you can have a fair few with you, but only need to carry the iPad.
So I think the idea of a digital Battle Missions: Death Worlds is a good one.
The Emperor’s realm encompasses a million worlds, each with its own potential dangers. Yet certain of these planets are so deadly that they are classified as death worlds. From man-eating flora and fauna to deadly poisonous atmospheres and many stranger things besides, on a death world it’s not just the enemy that your warriors have to worry about!
This Warhammer 40,000 supplement contains information on the deadly planets known as death worlds, as well as full rules for playing games with your collections across these unique battlefields. In addition, a comprehensive modeling and painting guide is included, full of easy to follow tricks and tips and suggestions for creating your own death world terrain.
Another advantage is that unlike a physical book you can leave it “open” at the right page, without needing to bend back the covers.