I used it here to make applications for Blogger (what I’m writing this on now), Out of Milk (the shopping list app I use), and Remember The Milk (which has the things I’m supposed to be doing instead of this).
In terms of technology, it’s simply an Electron wrapper around the site, but what’s pretty cool about it is that it does allow you to have each site in it’s own sandbox… but does two important things. First, you can see that each application has its own icon (in some cases, that I’ve defined myself) in my taskbar.
This is something you’re not going to get if you’re running, say, web versions of all your messaging apps in a different browser.
Second, unlike running a separate browser (or browser window), it’s trivial to open links from one of these created Electron apps in my normal browser where I do the heavy-duty work.
It’s also super easy to install Nativefier (and then super easy to install anything else) if you’ve already got Node/NPM installed. Highly recommended and available on GitHub.