Since that's been written, CocoaPods has added Swift support. As of a few weeks ago it's currently available in beta (gem install cocoapods --pre).

To the OP, CocoaPods is probably the most widely-used package manager, but there's also Carthage too, which is decentralised: https://github.com/Carthage/Carthage

It'd be nice if Apple had an official package manager but they seem to want to stay out of it (see Homebrew/MacPorts on OS X too).