Trevor recommend both the book and AudioTools to me a while back. I can 2nd both.
Of the books I've looked at this was the most concise and most practical one by far. Wish I had it when I was first planning my HT.
AudioTools also seems to be a really good app. I have not used all the tools yet but so far I'm happy. AudioTools come with a minimum set of plug-ins. All the others, some of which you'll want, are ala carte.
Instead, I bought AudioToolsMax which is AudioTools with everything enabled (including anything which comes out in the future). It was a bit pricey even on sale (think the sale was something like 30% off at the time). I justified it because it had tools not only for room measurements but a few others I knew I'd need sometime in the future (like testing THD and noise).
One Note: Audio out on the newer iPads requires some sort of interface now that they no longer have a phone jack out. I have an older iPad I'm keeping around which is good enough for room tuning.
