Here is a work around for downloading a PGN via your iPad, but I don't know of anything on iPad that can analyze it for you...
1. Download Goodreader on the iPad
2. Now Open Safari
3. Go to www.chess.com and locate the game, Click on the [GET PGN] button
4. It will open a new page with the URL of the PGN in the address bar and an icon on the screen with the file name
5. Touch the address bar with your finger twice and hold it till the magnifying circle appears, release your finger and the "cut, copy, paste" pop-up will appear. Copy the URL
6. Click the iPad home button and open Goodreader. Under Web Downloads in Goodreader is a button for [Enter URL], click it. Then paste the URL you copied from chess.com there
7. Goodreader will complete the download for you. You can view it in Text format and can copy and paste text from that screen.
But I don't think you can load a PGN into Shredder on the iPad.
I have shredder, fritz,and Stockfish on my iPad. Yet I can't seem to anayze the games I've lost on chess.com. When I hit pgn it just says safari can't download file. Why? I am getting a MacBook pro soon. Will I also have trouble analyzing my lost games with it? I am told that there is a nice free chess game with it and of course I could buy shredder but not if I can't Analyze my games. I must be doing something wrong. Any ideas? Stalls