Need App-specific Metadata for use with code that uses API

I'm finding a need to be able to add metadata to an App when I as an administrator define it.  For example in my specific use-case I'd like to be able to say that an App is "Task Related" and then be able to get a list of Apps and in my code filter out the ones that are not Task Related.  Currently I don't really see a good place to put App-related metadata when I am modifying an app.  Is there something I'm missing?