"Great extras" refers to additional things or benefits that are above and beyond the basic or expected features of something. It implies that these extras are excellent or desirable. Full definition
On top of that it's got a lot of great extra features, such as access to videos and books to help you with your venture into the dating world. (bbwsdatingsites.com)
This is amazingly creative and must provide great extra counter and storage space! (dearcreatives.com)