Who knew? You can get article level metrics for any recent paper, for free.

Reading a paper and want to find out how many times its been cited in social media? Install the free Altmetrics bookmarklet for Chrome, Firefox and Safari. To install the Bookmarklet, just drag it into your browser’s bookmark bar – this is typically underneath the address bar. The Bookmarklet works with PubMed as well as other webpages containing a DOI.

More information on the bookmarklet can be found here.