Some Wordpress plugins are often updated, which is good think. Plugins that are updated are 100% compatible with last Wordpress version and they also are the most secure possible. A plugin that has not been updated for a long time might not work with last Wordpress version and might create a security breach for you website.
Free Feedburner Alternative and RSS Redirect plugin from SpecificFeeds.com.
Track sales analytics, conversions and understand consumer behavior using google analytics (with ecommerce tracking) and facebook pixel.
Create short codes for almost everything in the Word Press and use in Pages, Posts or anywhere.
Extended Tagging for WordPress : Terms suggestion, Mass Edit Terms, Auto link Terms, Ajax Autocompletion, Click Terms, Advanced manage terms, etc.