No pocket/pc version of Navbox. They planned one but it never came.
No detailed maps in Navbox. The maps are more bare than Jepp's base maps, making it less than useful IMHO with a GPS input.
Flitemap (Flitestar with GPS input option) is adequate with the Jepp base data (if you have a printed chart to hand, and correlate the airspace shapes) and pretty slick with their Raster Charts. But it has been discontinued, though data updates are still available (they are the same as for Flitestar).
However, I was once flying along somewhere near Greece and found a ~ 5 mile error between Flitemap, and my KLN94/KMD550. I checked and cross-checked with VORs etc, and a PDA GPS running Oziexplorer. Flitemap was the odd one out. I rebooted the tablet PC and from then on it was fine. Very odd... just that one occassion but it has me worried. I don't know if this bug was quietly fixed with their update patch (on their website) which is meant to fix the "plain text" input mode crashing (and it does).