Now here's something I've been playing with for awhile. And for a free* app it's... the best I've found actually.
The app works completely off-line on your local device memory. Not only that but you can have multiple tournaments active at the same time. The only down-side I've found with this app so far is the restrictions of the free version* (which I use) only enabling Single Elimination, so regardless of 1-strike KO or Elimination Brackets, the outcome isn't really any different, no different at all.
The menus and layout are easy to understand and use, I would give instructions but really this app doesn't need them, just do what I did to test the app and run a tournament using your own decks. After that go ahead and ask players down your locals if their game for a little unofficial tournament.
Bearing in mind this is my ONLY negative this isn't really a bad thing, considering I am using the free version* of the app.
No version of this app supports Swiss drawn pairing which I do find is unfortunate but everything else is covered through one means or another, whether this is as intended or not is irrelevant it still does it.
The only part of the app that is a pain to navigate is the "tournament view"
On a closing note unlike typical free* tournament app, the cap of players isn't set at 32, in fact I'm yet to hit the player limit, what ever they may be.
I may not be the best at reviewing apps mainly as I don't really know what to look for in an app other that it being easy and fun (if applicable)
I approve. 8/10
* Too bad the "pro" upgrade costs £6 but you may find it worth it. That's a bit on the high side and unless I'm topping up my apple account with £15 so I can also buy an album from iTunes I won't be getting it. I don't like leaving cash/credit lying on an account. I'd rather top up and use all at once.