This final note, in which I am not, repeat not, quitting my job. (I got in a whole mess of trouble the last time I joked about that.)
But if I were, boy have I found a good way to do it.
It's called the Quit Your Job app.
You decide why you want to quit, it sends an appropriate text to your boss.
Also available from the same company?
The BreakUp text app.