Plugins extend and expand the functionality of concrete5. About 400 plugins are at your fingertips on the concrete5 marketplace, 20 of them which are developed by Devoda (Ramon Leenders). Missing a plugin in the Marketplace? Leave a message!
Make sure you leave a review once you've installed and used an Add-On. Leaving a review helps others decide whether or not the product is useful to them. The more users will be using an Add-On, more feature requests will be made and the more features you will be getting as well. So let others know what you think and let the developer know as well if there's something very important missing. You as a customer will be shaping products to fit everyone's needs.