I have been looking for a comprehensive book on Bluetooth programming since I started working on providing a secure IoT communications network for my home automation system a year ago. Actual code for Bluetooth is very hard to find and mostly consists of snippets on the internet.This book covers programming on two platforms in three different languages. And it covers both device discovery and actual intercommunications. I have to say that this is the book to have for Bluetooth programming.Android programming examples are relatively easy to find. The trick is to find Windows files and libraries. The header files for C programming have become very hard to get since Nokia absorbed the early Bluetooth libraries in 2007. So, if you want to have your Bluetooth dongle talk to your own network of devices, it's going to take some time scraping the internet to get a complete working Bluetooth header and a library to link into your code. Also, the book clearly differentiates the old Bluetooth from Bluetooth LTE.This book has helped me understand the code, the pitfalls, and the background to successful Bluetooth programming. Although the problem of producing a secure network among my devices has turned out to be a larger problem than I expected, this book has covered all the bases and given me confidence that I can find the answer to the solution with the material from this one book.