Pentango for the Pocket PC
Pentango is available for many older Pocket PC's (version 2000 or higher). Supported processors: ARM, SH3 and MIPS. It may run on newer models as well, but no guarantees.
Pentango is free. See the download page for download and installation instructions.
Helpful hints: For accurate placement of your pieces, tap, hold and move your stylus to the desired location. The piece will get placed after you lift the stylus (of course a simple tap also works). Alternatively, use the "arrow" controller of your PPC to move the piece locator and press it to place the piece.