I created a browser extension called TabFloater, which can replicate the picture-in-picture functionality with any website. It moves a chosen tab into a smaller window, which is going to remain always on top, so you can interact with both websites at the same time.
I have been working on this pet project for a bit over a year now. The motivation for it was simple: because I use my browser in a single, fully maximized window, many times I found myself switching back and forth between two tabs, for example to copy something from one website and use it on another. I know there are many extensions that can rearrange tabs for you, but I wanted something a little bit different. I really liked how picture-in-picture works for videos - I wanted to do the same!
The extension is available for Chrome and Firefox, and you can use it on Windows and most Linux distros. The native application doesn't have an OS/X version - sorry 🙂 I don't own a Mac and I don't know anything about the Apple ecosystem. I'm looking for help in that department, if you're interested! 🙂
Reminder: in addition to the browser extension, you must also install the native application (called Companion).
Video to see it in action: [https://www.youtube.com/watch?v=mePFebBvmWc](https://www.youtube.com/watch?v=mePFebBvmWc)
Chrome Web Store: [https://chrome.google.com/webstore/detail/iojgbjjdoanmhcmmihbapiejfbbadhjd](https://chrome.google.com/webstore/detail/iojgbjjdoanmhcmmihbapiejfbbadhjd)
Firefox Addon: [https://addons.mozilla.org/en-US/firefox/addon/tabfloater/](https://addons.mozilla.org/en-US/firefox/addon/tabfloater/)