mafaneh

Some good points there. I agree that things are accelerating at a rapid pace that's hard to keep up with!

What you're describing focuses too much on the implementation on a specific platform. It's true that each vendor will provide their own way of doing things (perfectly normal), and things will change as well (also expected). But you have to also keep in mind that there is a lot that can be learned about the Bluetooth protocol and technology itself that is independent of the platform its implemented on. If the developer does not understand the protocol and specification, then they will end up getting sucked into the implementation of the specific platform. I don't work for Nordic nor have any affiliation with them, but from my experience, their support is top-notch and I love the community interaction and support they offer through their DevZone site. No vendor is perfect, so it goes without saying that there will always be pros and cons.

Also blank in Chrome on iOS

First, a disclaimer that I'm the author of the e-book listed.

Yes, I agree that getting BLE to work with smartphones is not an easy task. The APIs are ever-changing and evolving and differ across different devices as well. In the end, though, they must adhere to the official specification and provide an interface to the underlying protocol.

There are many embedded developers that are looking to learn the protocol and don't know where to start (myself included, especially when I first starting learning the technology). The specification is quite overwhelming and there is a lack of resources that cover both theory and implementation together.

The book is targeted at embedded developers with the goal to help them learn the basics of the technology by guiding them through various exercises and examples. There are also many new use cases popping up where an embedded platform is used on both ends making the task easier (compared to pairing with a smartphone app).