Custom Buttons?

I am sorry if this is put on the wrong forum, because I do not know which place is more correct to put this in. :)

I am here just to ask a simple, yet may be impolite. Just at first glance, I am very amazed with how you done with these clickable buttons above the text area. I have seen it once before on Wordpress, but still not understand how to implement the same feature on Drupal.

Could I ask you which module you are using? Or how did you do this on the first place?

Thank you very much for the response.