Visual Changes in the Post/Page Editor

Hi,

I just installed this plugin but I cannot see anything in the editor area to tell me that it is installed or working. I have deactivated all my plugins except for this one. Documentation is very scant nor screenshots after activation are not available. Please advise. I also activate the 2012 theme.

https://ww.wp.xz.cn/plugins/wp-front-end-editor/