Version 1.0 was originally commercial, sold through JoyGP, but at the launch of the BLU, it was released into freeware, bundled with the offical drivers cd.
It is also available on some websites, and Evildragon has a copy of it. That was the copy available at gp32x.de, until 2.0 came out. I'm guessing he will eventually put 1.0 back in the archives for BLU+ support.
EDIT: Found a copy on gp32eu.com, in .FPK form, just extract it with the package extractor.