I was never really into trackers, so I doubt that you are going to get a good idea of what the tracking capabilities are. What I can do is tell you about the tracker applications I know about that run on PDAs.
This application runs fine on my Dell Axim although I have spent very little time on it so far. It is worth a look if trackers are your thing, and is being continually developed.
This is an application I know very little about indeed. Psytexx has been around for some time and is a cross platform application as well as being open source.
Mobi tracker is another app I know nothing about, but also runs on a platform I know nothing about.
As far as I know that's it in terms of tracker apps, but if you know of more, please let me know.