PlayStationHaX developer cfwprophet has released an application he calls ‘PS3 SFO Batch Category Patcher’, here is a quote from his thread:
What it does?
It Batch Convert the SFO’s (or only one) Category of a PKG file. You put a pkg or more into the folders app, run it
and choose the new category to patch and click the button. Usefull for CFW/MFW with custom categorys in the xmb.
In short, it helps you to put your app’s/pkg’s into a other category then the Game collum in XMB.