Books
RxJava for Android Developers
If you were confused about Rx or RxJava, this book does a great job of a practical explanation. Its still in early access as of 12/20/17.
Cracking the Coding Interview
Found this book to be very useful, good example problems and content just for your own enjoyment of solving if your not interviewing.
Tao Te Ching
An ancient Chinese text that loosely means "The way" however the nature of "Tao" is that it is unknown and cannot be translated. The Stephen Mitchell translation is recommended for westerners.
The Power of Now
Your reality will change after reading this. If you are ready for enlightenment you will keep picking it up again.
Illusions: Adventures of a Reluctant Messiah
An interesting story, recommended by a few sources to me.
Tech
Blockchain
Seems to be on everyone's radar a secure decentralized tech for alt-currency tech, its quite amazing what netgineers have done with it. Notably cryptokitties and for music artists Ujo.
Interplanetary File System
Peer-to-peer for the web. No more central servers dictating uptime. More security features. View on github.
Docker and Containerization
While less secure than virtualization, it has proven useful for a lot of things. Such as microservices, testing on difference environments and giving consistency to builds/deployment.
Reactive Extensions
Interesting, misunderstood tech (not the javascript web framework). There is some math behind it all.
American Fuzzy Lop and Fuzz Testing
Lots of security patches due to this project from a google employee (see the trophy case).
Phoenix Framework and Elixir/Erlang
This promises to be a modern, ruby-like, easy to use web framework that delivers the scalability and stability of the erlang virtual machine.
Keybase
A nice solution for managing encryption and keys. Has a auto-encrypt file system and a chat client.