This simple utility lets you manage your Soundflower audio interfaces easily and effectively. It also takes care of unloading and reloading Soundflower's kext to apply your changes. You can find the binary of the latest version in the releases page.
This project is no longer maintained, as I no longer need SoundBlossomer. I rely on Rogue Amoeba's excellent Loopback app, and I suggest you do the same, it's way more stable and polished than Soundflower+SoundBlossomer ever were.
Just download the .app and run it, it should be pretty easy to get started. Or if you're a real nerd you can download the entire Xcode project and compile it yourself, how cool is that?
Basically, it reads Soundflower's Info.plist file, checks for existing audio interfaces and allows you to edit, add or remove them. Once you're done, it can either write the plist back and reload Soundflower's kext to apply your changes, or just save the plist without reloading.
OS X 10.10 Yosemite now prevents unsigned Kexts from being loaded. Soundflower's is not signed at the moment, so it won't load with OS X's default settings. As a workaround, you can enable unsigned Kexts by running
sudo nvram boot-args="kext-dev-mode=1"
and then reboot.
Soundblossomer is BSD-licensed - you can do pretty much whatever you want with it.