We started writing this book on November 2013. The initial goal was to provide guidelines to write the most clean Objective-C code possible: there are too many guidelines out there and all of them are debatable. We didn't aim introducing hard rules but, instead, a way for writing code to be more uniform as possible across different developers.
With time the scope moved to explain how to design and architecture good code.
The idea underneath is that the code should not only compile, instead it should "validate". Good code has several characteristics: should be concise, self-explanatory, well organized, well documented, well named, well designed and stand the test of time.
The main goals behind the curtain are that clarity always wins over performance and a rationale for a choice should always be provided.
Some topics discussed here are general and independent from the language even if everything is tied up to Objective-C.
Alberto De Bortoli