Shared helper classes
I have used SwiftyBeaver for logging in previous apps. It has the downside of adding a third party dependency to my code and introduces an overhead that I don't need for development. Remember, this isn't supposed to be an app log for use on released code, just a lightweight way to log actions during development. SwiftyBeaver was total over-kill for this but was also a great tool.
WriteLog is my lightweight alternative that gives me just enough logging to be useful without the overheads of a web logging system.