Alcatraz is an open-source package manager for Xcode 5+. It lets you discover and install plugins, templates and color schemes without the need for manually cloning or copying files. It installs itself as a part of Xcode and it feels like home.
To install, open up your terminal and paste this:

curl -fsSL | sh

or download the repository from Github and build it in Xcode. You’ll need to restart Xcode after the installation.
Alcatraz requires Xcode Command Line Tools, which can be installed in Xcode via Preferences > Downloads.