As an FYI - this app is somewhat limited. Unless they find a way to make multiplayer go against other online players.
I finished up the campaign in a few days. The sealed gives you 2 tournaments - then wants $ for each add'l. You have replay value as you can play each of the decks through to get additional cards to improve them (35 cards per deck - there are 10 decks). The campaign itself is 4 duels per "plane" and there are 4 planes (as I recall). There are also 5 planeswalkers to defeat.
Lastly - it only offers cards from the 2014 Core set.
As far as the AI - I just realized there are 3 difficulty levels and mine was set to the easiest by default. I changed that and I'll see how it improves.
(I still really like it though, with those drawbacks - mostly because I've got no other Magic outlet right now - except the ancient Shandalar which I've finished too many times to count.)