ResponsiveVoice the leading HTML5 text to speech synthesis solution, is now available for WordPress. Over 51 languages through 168 voices.
Text Captcha uses riddles and math to make sure your posters are real instead of computers.
When pasting images, alchecker checks whether alt attributes are correctly filled.
This is a very accessible and custom made YouTube-plugin for WordPress.
Plugin for blind and purblind administrators of WordPress.