If you liked browsing through peoples diaries in the game and you've seen some basic script code before then I'd recommend you to take a look at the combined.js that sits in the game's installation folder.

While not as explicit as the game itself this file is just as interesting with all the comments and TODOs in it, besides the code basically explains how this iOS version of the game works (e.g. what condition must be met to get a certain ending, how the card game works, ...).