Tactical Objective App

So of course after buying two different sets of objective cards (don't judge me I wanted the eldar psychic powers and the cards happen to come with) someone went and designed an App for it. Appears to be endorsed by GW as well (which is nice). Does seem rather expensive since the app itself is 7 bucks and then each specific add on deck is another 4? I probably would have bought it if I didn't already own two decks.

https://itunes.apple.com/us/app/warhammer-40-000-tactical/id990952051?ls=1&mt=8

Well considering each deck cost $15, even if you own several (I have the base deck, DA, Cadians and SM), the first new faction effectively is the same, after that you save $11/deck.
Only really works tho if you have several armies or are an anal retentive completist.
Between these, the dice app, and the gamers edition.... I'm really debating owning and books going forward.