Mac OS X Picture in Picture
Always on top window preview similar to the popular windows only OnTopReplica
cmd+nto open and
cmd+wto close
cmd+p
brew cask install amitv87-pip
# checkout code git clone https://github.com/amitv87/PiP.git cd pipbuild using xcode
xcodebuild open build/Release/PiP.app
or simply
./run.sh
right click on the window and select an option from the list
right click again and select last option to crop the preview