"Theory of Pistachio" is an Android app developed by smart.app in the category of Education & Reference. The app is a simplified book written by Fahad Amer Al-Ahmadi, a Saudi author, covering several topics such as self-development, neuro-linguistic programming, consciousness, and human behavior. It is a comprehensive guide that consists of seven chapters.

The book covers topics like, "What's your plan in life?", "Know yourself first", "If you don't dream of it, how will you achieve it?", "Don't think of succeeding, think of creating success", "Theory of Pistachio", "Twenty rules at home", and "Small life instructions". The app is free, and it doesn't require an internet connection to read the book. It is an ideal app for people who are looking for self-development and want to learn about human behavior.