Worth a fiver I reckon.
There are a lot of random events and things to remember at the start of the turn ( cave ins, gas bubbles etc.) that are designed to add flavour, but we quite often forget after the first turn! There's a rule that affects shooting that doesn't bother our two Orc armies, but may be tiresome for Elves...
Beyond that you've got a few unique scenarios and some campaign rules for generating the battles and stratagems you can use to influence the games.
There's also a campaign tracker to record your games, but we can't get it to work!
If you're a tournament or "competitive" style player, then its probably not for you - unbalanced forces and too many random events - but if you're looking for something to add variety and link your games with a regular opponent then its ideal.
Nothing earth shattering, or that any reasonably experienced Warhammer player couldn't do yourself in a few hours, but good fun and value for a fiver ( if you ignore the several hundred pound iPad you also need).