When to read the book
AI, or its hottest branch machine learning, or its hottest subbranch deep learning, has enjoyed rapid progress in recent years. New releases of TensorFlow, backed by Google and with the most popular developer community of all open source machine learning frameworks, has also been launched at a faster speed. When we started writing the book in December 2017, the latest TensorFlow release was 1.4.0, released on November 2, 2017, and after that 1.5.0 was released on January 26, 2018, 1.6.0 on February 28, 2018, 1.7.0 on March 29, 2018, and 1.8.0 on April 27, 2018. All the iOS, Android, and Python code in the book has been tested with all those TensorFlow versions. Still, by the time you read the book, the latest TensorFlow version likely will be later than 1.8.0.
It turns out you don't need to worry too much about new releases of TensorFlow; the code in the book will most likely run seamlessly on the latest TensorFlow releases. During our testing run the apps on TensorFlow 1.4, 1.5, 1.6, 1.7, and 1.8, we've made no code changes at all. It's likely that in a later version, more TensorFlow operations will be supported by default, so you won't need to build a custom TensorFlow library, or you'll be able to build the custom TensorFlow library in a simpler way.
Of course, there's no guarantee that all the code will run without any changes in all future TensorFlow versions, but with all the detailed tutorials and troubleshooting tips covered in the book, no matter when you read the book, now or months later, you should have a smooth time reading the book and running the apps in the book with TensorFlow 1.4-1.8 or later.
As we have to stop with a specific TensorFlow version at certain points to get the book published, we'll continue to test run all the code in the book with every new major TensorFlow release, and update the code and test results accordingly on the book's source code repository at http://github.com/jeffxtang/mobiletfbook. If you have any questions about the code or the book, you may also post an issue directly on the repository.
Another concern is about the choice between TensorFlow Mobile and TensorFlow Lite. The book covers TensorFlow Mobile in most chapters (1 to 10). TensorFlow Lite may be the future of running TensorFlow on mobile, it's still in developer preview as of Google I/O 2018—that's why Google expects you to "use TensorFlow Mobile to cover production cases." Even after TensorFlow Lite is officially released, according to Google, "TensorFlow Mobile isn't going away anytime soon"—in fact, with the latest TensorFlow 1.8.0 version we tested before the book's publication, we found that using TensorFlow Mobile gets even simpler.
If the day that TensorFlow Lite fully replaces TensorFlow Mobile in all use cases, with Lite's better performance and smaller size, does finally come, the skills you'll learn from the book will only better prepare you for that day. In the meantime, before that unforeseeable future arrives, you can read the book and get to know how to use the big brother such as TensorFlow Mobile to run all those amazing and powerful TensorFlow models in your mobile apps.