Great, and Great for Studying too

As other users say, its needless to say the engines strength of tChess Pro.
Honestly speaking, to me, the maximum setting of tChess Pro is only necessary when I analyze a game. :)
Among its features, I love "importing .pgn file" most. This is an essential feature in learning tactical patterns which many grandmasters think is the crucial training.
For my example, I made a pgn file by myself while studying a chess book, uploaded it to google docs, go to my google doc folder with Safari on iPod, there is already a button named "open with tChess Pro". (There might be more ways to import .pgn, like iTune doc, though I didnt try all. I tried Fritz, but realized that it can download chessbase file from only their server. or Copy/Paste - much more steps to get it done.)
As a chess learner, Id like to suggest one impromevent to Tom Kerrigan. (Long time ago, I studied his TSCP to study how to make chess engine, his code was simple, clean and efficient)

* (suggestion) Navigate games in one database(pgn), like Next/Prev Game

However, even without this, its already perfect portable chess software.
Thanks Tom
P.S. for those who hesitate to buy because of blue and marble chess board in screenshots, Id say tChess Pro also has a wood chess board option.

tidynail about Chess - tChess Pro, v1.5.5