The Peer Review closer is a small utility that will automatically close a peer review, per the instructions at Wikipedia:Peer_review/guidelines#Step_4:_Closing_a_review.
Installation edit
Add the following line:
mw.loader.load("/w/index.php?title=User:Writ_Keeper/Scripts/peerReviewCloser.js&action=raw&ctype=text/javascript");
...to your common.js page on a new line (it's okay to create the page if it doesn't already exist).
Usage edit
On a peer review page, you should see a new option in your editing tools along the top that reads: "close peer review". Simply click that button when you're ready to close a review and everything should be taken care of for you! If the script is successful, the page will reload and you should see the close taking effect. If a problem happens, a small notification will pop up, informing you of what went wrong; either the peer review page or the article's talk page (or both) might need manual intervention if they don't contain the standard peer review templates.
Uninstallation edit
Simply remove the line you added in the installation page from your common.js page. Easy!