I don't think these ever made it out the door. There's some info/code in the Commodore server dump that was circulating a year or two ago. The build of appshell.library in that archive is dated May 13, 1992, so I think this was something that CATS canceled, as opposed to it being ended by the bankruptcy. There's also an older release notes file (May 1991) that makes reference to appshell.library, appobjects.library, prefs.library, and hyper.library.
Of those, hyper.library is the only thing I recognize/understand, since it was an early name for what eventually became amigaguide.library. prefs.library appears to be an abandoned concept for a preferences system that was never fully implemented. I don't really understand what appobjects, appshell, and AppBuilder would have done.
Interestingly, there is also some archived correspondence from Inovatronics about AppBuilder, suggesting that Commodore may have outsourced development to them. I thought maybe AppBuilder eventually became CanDo, but the first release of CanDo predates all this work, so that's probably not the case.