Have you seen this web page?
Compare SkyDemon Versions
Skydemon mobile IS the version you install on a Windows CE device (which I presume is what you mean by your PDA). You can't install it on a Windows mobile device.
Just remember that you need an additional subscription to use it "in flight" - you get a 30min demo if you don't have an additional subscription - then it will stop mid-flight.
If you want to try it on a windows CE device - they are only about £40 on ebay for devices which have fairly decent screens. They don't pretend to have the quality of the branded skydemon device but at those prices they are worth a punt. Go to the SkyDemon forums for examples.