Chrome //
Extensions 
Chrome
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YouTube Rewind & Fast Forward Buttons
Add Rewind & Fast Forward buttons to videos player in a YouTube site
FFMSB (Freedom for mouse side buttons)
Prevents history navigation using forward and back buttons on your mouse
Enable all disabled buttons and inputs
extension enables disabled html elements, buttons,texareas, inputs and etc. test it https://s.codepen.io/bumbeishvili/debug/BzzYom
Grey Scrollbar with buttons
Widens and darkens the scrollbar and adds back the buttons. Uses css only.
Akonter Share link & Page Buttons
Chrome Extension to share links and pages to multiple networks, Akonter bookmarks, Facebook,Twitter,Google+ and more share buttons.
Mathematica Editor-buttons for StackExchange
This browser user-script adds additional buttons to the Q&A editor on mathematica.stackexchange.com
Alternate Navigation Buttons
This extension places a back and forward and goto top button on the page near the bottom of the window
