Here, this. I found really good. It starts of and you just go yes ,yes, next question please…yawn
…then you have to wake up! challenging towards the end and so rather educational.
and here is Rocketship tour through the solutions if it drives you mad, by our very own @itsmeleo,
And WHERE? I hear you ask is the Kitty?.. gah! so impatient!
here you go, with a kitty too. -youtube tutorial