PocketFrog 0.7.0 and lower still use GAPI, so they require the full screen.
Not entirely correct. GAPI can only be run in full screen mode - yes. And PF use GAPI for devices that support GAPI. But for desktops and older PDA:s PF wrapps the W32 GDI and for those platforms you can most definately use PF in windowed mode (I did this myself a year ago for a masters thesis on using 3D for visualizing maps on a PDA).
If someone is interested in the main code (i.e. what changes are needed of PF to allow this and also to allow multiple windows) have a look here:
http://www.nada.kth.se/~t98_hes/pf/