WIKI: "Pocket Fritz, which is currently at version 2, is a chess playing program for the Personal digital assistant (PDA). It is a port of the Shredder chess engine.
Since the popularity of the PDA came about in the 1990s, some chess programs have been written for the portable market. This has also been in response to the increased popularity of chess in recent years.
In common with a lot of software for PDAs, there are a number of chess programs of very mediocre quality. In a very thorough and comprehensive review of 63 chess programs for PDAs by Dr. Axel Schumacher, he found some did not even know the rules of chess, with at least one moving the king, then castling. Pocket Fritz 2 was rated third in that review, behind Pocket Grandmaster (commercial) and CE Board (free, but not open-source). Hence Pocket Fritz 2 is clearly one of the better chess programs for Pocket PC. HIARCS v9.5 for Palm  was rated number 5 in that review, although that was the first program on a PDA to beat a grandmaster, when on 22nd Jan 2005 it beat GM Jan Gustafsson twice, and drew twice in a 4-game match. However, pure playing strength is not the only indicator of the quality of a chess program. The quality of the graphical interface is important, with many programs being very poor indeed. Pocket Fritz 2 claims to have an estimated blitz performance rating of 2450 Elo points.
The strength of chess programs on PDA will never be as strong as on larger computers, due to the slower processors and more limited memory.
The web page for Pocket Fritz 2 states that the program can connect to the Chessbase server and allow you to search for the current board position in more than 2 million games on the server. This is no longer true, as that functionality was broken in early 2006 by changes on the Chessbase server. According to Chessbase a high priority to fix, as was detailed in an email to Dr. David Kirkby part of which is shown on the one of the chess newsgroups."
Fritz and Chessbase