Since Chrome 70, Google introduced Picture-in-Picture (PiP) and enabled by default. You can now select a video and enter PiP mode to watch video across tabs & window by right-click context menu on theoretically any modern websites. That is awesome and good for multi-tasking. However, there are some limitations with this function.
Limitations for native PiP: 
- Websites that block right-click context menu not supported (Facebook, Netflix, almost any)
- Need to manually turn on/off PiP mode on a single video
But with this extension, the video is always here and you can fully experience how PiP make your life easier.
1. Auto create floating player when switch to other tabs/windows
2. Auto disable floating player when back to the video tab
3. Prioritize multiple videos and show the one that you need
4. Support any Window applications and any modern websites (Youtube, Facebook, Twitter, etc)
5. Since v.0.2.0, added popup for blacklisting websites & domains
6. High performance promise-based extension in native Javascript, very lightweight
(More and more)

Possible upcoming features:
1. more flexible extension config
2. multi-language support
3. more convenient functions with floating player custom control (Google has been working on it)
(You may suggest more)

Work on both Windows & MacOS now!
Please note that this extension requires permission to observe every videos in all websites.
Report bugs and feel free to give me suggestions :)

change log - v.0.2.0
Enhancement:
1. added popup with blacklist function
2. more intelligent mechanism for Mac OS users
Bug fix:
 - PiP is now blocked when the window is maximized since chrome in MacOS does not allow PiP in maximized windows

change log - v.0.1.81
Enhancement:
1. improved stack algorithm to enhance stability
2. simplified system structure, faster & less memory used
Bug fix:
 - incorrect sorting algorithm

change log - v.0.1.76
Enhancement:
1. improved algorithm to auto enter PiP mode in a more friendly way
2. when at the video tab, it triggers PiP only if the window is maximized, minimized or not maximized but the video is scrolled to an invisible position
3. stack algorithm improved
4. auto disconnects videos in discarded tab
5. enhanced window & tab switching detection algorithm, more different circumstances covered
6. added Bluebird to enhance the async performance at runtime, faster with less memory used
-- Milestone - the extension is more complete and stable now --

change log - v.0.1.54
Enhancement:
1. improved stack algorithm to enhance stabity
2. added update notification when extension updated
3. auto update & reload extension if update available
Bug fix:
 - no reaction when opening new window in chrome

change log - v.0.1.40
Bug fix:
 - sometimes it failed to enter PiP 

change log - v.0.1.35
Enhancement:
1. added stack to enhance the stability

change log - v.0.1.29
Changes:
1. removed PiP when you switch to other window in the video tab since it's not desired in most cases

change log - v.0.1.28
Enhancement:
1. more reliable detection when switching to other applications in the video tab

change log - v.0.1.27
Enhancement:
1. no need to reload pages when updating / restarting extension
2. video keep playing if it was discarded from PiP mode
Bug fix:
 - when switching tab between main player and other tab too qucikly, it blink and keep enabled
 - sometime two video may wrongly received message from each others
 - not detecting the status when a video is aborted

change log - v.0.1.26
Enhancement:
1. a bit more accurate video detection

change log - v.0.1.25
Enhancement:
1. more reliable and efficient core system
Bug fix:
 - sometime enabling PiP when switch to window application will be fail
 - prioritization may have issues in some edge cases

change log - v.0.1.18
Bug fix:
 - sometime after closing video, the extension wrongly detect its existence

change log - v.0.1.17
Bug fix:
 - sometime video cannot enter PiP automatically

change log - v.0.1.14
Enhancement:
 - performance boost
Bug fix:
 - new version cannot detect the status of video when first loaded the page

change log - v.0.1.08
Enhancement:
1. auto start PiP mode in other tabs when a new video started playing
2. performance boost and more new technique applied
3. PiP request mechanism more reliable, reduce the chance of request failure
Bug fix:
 - fail to enable the PiP mode of a video for the first time when switched to other tab already
Others:
 - no webpack using temporarily because of obfuscated code

change log - v.0.1.02
Enhancement:
- support Window applications trigger PiP now
- webpack & vuejs used for production now, thanks to ALiang Liang
Bug fix:
- video prioritization issues

change log - v.0.1
--extension beta version released--