iPhone app for viewing and analyzing PGNs

I'm searching an app for my iPhone, that has the following features:

1) Viewing pgn files including variations (seeing comments would be nice but is not necessary) and reading pgn files containing multiple games

2) Analyzing the position from the pgn files at any time (something like the 'analyze bord' feature here on chess.com), that means making some moves on my own and then returning to the game from the pgn

3) Transfering the pgn files via iTunes directly to the app

4) Analyzing the position (from the pgn or in the 'free analysis mode' described in 2) with a chess engine (this feature is the least important to me, if features 1 - 3 are met, I could pass on this if there is no better option)

I already tried some free apps:

- Chess Viewer: doesn't meet 2) and 4)

- Chess Free by Christophe Theron: doesn't meet 3) so i wasn't even ably to really test

- CBase Chess: doesn't meet 2) and 4)

- Stockfish: Doesn't really meet 2) - when making a move that's not in the pgn game, it's not possible to go back to the original moves and continue viewing the pgn at that point (at least I didn't see how)

It doesn't have to be for free. I would buy a suitable app but I don't want to buy one just to see it's not what I'm looking for.

Does anyone know such an iPhone app? Any recommendations?

I'd appreciate any suggestions 

I finally found something. It's tChess Pro:

http://www.tchessgame.com

 At first I wasn't sure, if it had all the features I was looking for, so I e-mailed their support. It only took the author 2 minutes to answer my questions and he was very nice and helpful.

 I've been testing the app for an hour now - it's awesome  if you're looking for something similar, it's worth the money!

Cool advice! Thank you for keeping us up to date ;-)!

smallfish