RPG84

On edit.php you will be able to see the currently used featured image for a post. Now you don’t have to open a post to add a featured image. You can do this from the edit.php screen.

Easy Featured Image

Easily edit and see featured images on your post edit screen.

ChefGaby

This plugin will help you add the official twitter button in your articles. It’s easy to customize and works right after activation. 
You will be able to choose where the button shows up inside an article, what type of twitter button to show and what text to submit when a user clicks the button.

Easy Twitter Button

Add the official twitter button in your articles

Easy Featured Image vs Easy Twitter Button