MailPoet comes with a “subscribe in comments” option that allows visitors who comment on a post to subscribe to your list via a checkbox. But this box is unchecked by default. With this jQuery snippet, you can have the box auto-checked on page load.
By default JetPack adds a nofollow attribute to all links in the related posts section. You can use this PHP code snippet to remove/disable this nofollow attribute.
PHP code snippet to test whether a user has a valid Gravatar or not. The only input needed is the user’s email address. It uses MD5 hashing and URI response headers.