Fluid is a Mac OSX app which can convert a single website into an application, with its own icon and place in the dock and task switcher. It is a great way to get the desktop like application feel for a web app.
This works particularly well for single-page apps like gmail, or Trello. The app can be set to not close the window on close, just hide which leaves gmail running in the background, and lets trello remember the last board you were looking at.
The amount of customisation is incredible, and user scripts and styles are enabled by default[^1].
I was a bit skeptical as I noticed quite a high memory usage, but after investigation found that it was only the memory usage for the web app anyway (thank you chrome for your task manager...)
So I encourage any heavy users of "single page apps" like the ones mentioned above, or any websites in general to get a bit of fluid in your dock.
... that was awful but I'm too busy to change it...