Alcatraz allows you to install different Plugins, Color Themes, and Templates for xCode. This is very different from CocoaPods, Carthage, and Swift Package Manager which focus on helping app developers discover and install libraries and frameworks created by the community.
Alcatraz is really more intended to help you pimp out your xCode.
My favorite plug-in within Alcatrax is AdjustFontSize. It makes it very easy to increase and decrease font sizes using Control + or Control -.
I also prefer viewing code in midnight mode. There are a ton of really nice color themes within the package manager.
The templates section is great for new Swift developers. I specifically use this Singleton template because there are like 2 or 3 ways to accomplish a Singleton in Swift.