Helium by JadenGeller pour Mac

Use the "Developer website" link above to download version 1.9.

I wish so much this would become an alternative to the excellent but outdated Afloat by allowing, not only the browser window, but any window to be kept on top of others.

Helium is a translucent, floating browser window. Some great ideas are self-evident, requiring only a brief explanation for their impressive qualities to take hold and excite. But more often than not, it takes actually seeing something in action for it to dawn on you how incredibly revolutionary it can be for you. So when a coworker suggested Helium for Google Hangouts and I tried it out, in an instant, the app entirely justified its place on my Mac. In a few clicks and keystrokes, I was video chatting on a see-through window, free to fill my screen with the tabs and documents that I typically have to keep entirely or at least partially hidden away while participating in a conference, and free to click directly through the video chat, onto things that were still visible behind the window. A super simple interface emphasizes Helium’s no-nonsense approach: enter a URL, enable translucency, select opacity, and you’re on your way. In order to make any changes to your browser window you’ll need to switch applications back over to Helium since it doesn’t register clicks when the app isn’t at the front, but that’s part of the beauty of the app. It’s minimalist in all the best ways: no unsightly address or bookmark bar adorns the browser window. With such an emphasis on simultaneously streamlining the browser but keeping it fully-featured, Helium doesn’t sport the most fluid browsing experience, but the whole point is for a page to be loaded and then set aside, meaning the moment-to-moment browsing experience is almost entirely unimportant. Give it a try and you’ll love what you (can now always) see.

This app is really slick. I've been using it to keep Google Hangouts in view while working in other apps/browsers. Good idea, well executed.