Stackblocker：This blocks the individual elements of the sidebar on Stack Overflow (and adjacent sites). Users are able to individually check which parts of the SO sidebar to block. Click the orange circle in the toolbar to edit preferences...
Stack Overflow is a great resource, but its hot network questions and general social media-esque can lead to distraction. Stackblocker allows a user to hide various parts of the stack overflow sidebar to lead to greater flow. You can customize the exact pieces you want hidden.