Globally accessible helper class
This design pattern is known as a Singleton, and you can read more about them here.

It's super easy to set up a singleton in Swift, and when I use this pattern I forward all method calls to the shared instance of the class.

class Singleton {
    static let sharedInstance = Singleton()

    // type method (aka class method), allows for easy-access code
    class func doSomething() {
        // forward the method and any parameters to the shared instance
        sharedInstance.doSomething()
    }

    // instance method, visible through Singleton.sharedInstance
    func doSomething() {
        println("Did something.")
    }
}


And the usage would be like so:

Singleton.doSomething()
Singleton.sharedInstance.doSomething()


(Both call the same method, just the first one is more concise)

Notes:


Apple is calling class methods in swift type methods
I use camelCaseForMethodNames because it is a convention (instead of CapitalizingEveryWord like class names)
People tend to have mixed opinions about Singletons (read more about that here, if you desire).