gistfile1.swift

import KeychainAPI

let keychain: Keychain = Keychain(service: "com.secondgear.myapp", accessibility: Accessibility.WhenUnlocked)
let userAccount = Account(userName: "[email protected]", secret: "lovesecretsexgod")
keychain.add(userAccount)

let fetchedAccount:Account? = keychain.accountFor("[email protected]")
if (fetchedAccount != nil)
{
    fetchedAccount?.secret = "newpassword"
    keychain.update(fetchedAccount!)
}

keychain.remove(fetchedAccount!);