I'm quite amazed at how responsive it feels compared to sharelatex or the likes. It's extremely simple. I like it. I may not use it myself, but I'll mention it to friends who are learning LaTeX.
I run the ShareLaTeX open-source version and it renders a PDF each time I want to see the changes I made. With ShareLaTeX I can exactly see how the end product will look, something you can't do with this app. It's much less responsive, but having a PDF is a bigger advantage to me.