Something I've wanted is a program full of blank templates with different kinds of tables that you put stats in. You insert the info for your codex then the program would translate it into app form. You could customize your own codex! It would allow you to add forge world rules in with the rest of your codex, along with your allies, fortifications, army list, and fliers. You could have all the info you would ever need right in one spot. You could change the order of the pages, font, size, etc.

If you put some of the work into the hands of the user then you wouldn't have to wait around for GW to do it, and it could be used for other gaming systems.