Select email recipients in WeBWorK by pasting in a list of usernames
This Chrome extension is also available from the Chrome Web Store.
WeBWorK is an open-source online homework system. It has a built-in email feature, to which this extension works adds a box for entering a list of recipients. This is convenient when the class is large and the recipient list is generated by some spreadsheet filter. Just copy the usernames from your spreadsheet, paste into the box marked on the screenshot, and click "Select these users".
License: WTFPL