Visual Studio Code
Once you fall in love with your development tools, especially your text editor, it is always very hard to switch to a new one. The integrations you have to do to set up a new environment, the shortcuts you are already used to, the plugins that make development easier and faster, etcetera.
I was reluctant at first when I saw Visual Studio Code (VS CODE) and all the praises about it online, but at pre-boot camp, I decided to give it a trial and it has been a game changer for me. Setting it up is relatively easy, it even comes with Emmet support, IntelliSense, Version Control built right into VS CODE, with no extension required.
To make it even more mind blowing, there is an extension marketplace where you can install additional extensions, it is home to a very vast amount of extensions that make development easier. For example, the ES6 Mocha snippet which suggests code completion via IntelliSense, this has made writing tests easier for me.
I have had several other interesting tools that I have worked with but VS CODE currently stands out as the most interesting and enjoyable for me. I am hoping to explore even more tools over the course of this boot camp that will make me more efficient and faster.