I'll keep this repo for historical reasons, and maybe there even are some categories you might need. But generally, it's not used anymore, not supported, not converted to ARC, and if you ship that you have to be careful to include all open source licenses.
Generally, big repos of categories are a BAD idea, and I see many developers doing this. Better be selective, just pick what you need for a project and don't carry around dead code and pullute the namespace with 10.000 categories. This will just slow your app down for many reasons (e.g. every Framework you link has a small startup time penalty.)
Also, while I am not a fan of prefixing categories, it definitely is needed if you're working on a 3rd party framework like http://PSPDFKit.com. So keep that in mind, category clashes are super hard to debug.