If you're the kind of person who had fun hunting down and completing all the codex puzzles in Assassin's Creed 2, then are you ever in for a treat. The Guides looks like it's going to be a very robust collection of similarily odd, seemingly disconnected, and quite challenging puzzles.
There are supposedly hundreds of the things, and they require a variety of code-cracking tricks and ciphers. Thankfully there are some tools that have been included (i.e. binary code cheat sheets and the like) to help you out a little. But not too much. You're still going to have to figure most of it out on your own.
The Guides will be available on the App Store for a special launch price of $0.99 (regularly $1.99) on August 17.