[hex13]

Imagine that you have to create website on your laptop.

With semi-transparent editor window and with live reloading, you are able to modify website code and see instantly how website changes underneath. Without switching apps.

[trabianmatt]

My favorite variation of this is to have a special keystroke for saving a file and making the window transparent at the same time, then restoring the opacity on the next keystroke. I can see the effect of the live (or hot) reload and then either continue editing or cmd+tab to the browser if I need to interact with it.

[mintplant]

A second monitor works even better - one for code, one for the preview.

[davidcelis]

But it's also more expensive and less portable. The transparency makes it easy as someone who is out and about doing work at coffee shops.