XFDcloser gadget (source) – Close XfD discussions at AfD, CfD, FfD, MfD, RfD, and TfD, including actions to implement closes (e.g. deleting pages for "delete" results, removing nomination templates and adding 'old xfd' templates for "keep" results, etc)
Close XfD[1] (source) – Adds the latest semi-automated closure tools for XfD discussions (AfD, CfD, FfD, TfD, etc.)—accessible either in-line or via a tab at the top of standalone XfD discussion pages
CSD Helper (source) – helps admins delete speedy deletions much more quickly, including changing rationales, and assists everyone in declining/contesting speedy deletions and changing speedy deletions to PRODs
responseHelper – Makes it easier to respond to requests/reports at WP:AIV, WP:ANEW, WP:PERM, WP:RFPP and WP:UAA. Links are added to your sidebar to quickly insert administrator notation templates and supply an informative edit summary.
Timotheus Canens' spihelper.js – essentially a must if you regularly work at WP:SPI
GeneralNotability's spihelper.js – an updated version of the above
