This plugin shows post/page/category/tag/comment/media/user IDs on admin's edit post/page/category/tag/comment/media/user pages. You can see the ID when you visit an edit post/page/category/tag/comment/media/user page. Since this plugin hooks on 'edit' link, only users with priviledges can see IDs. For example, a user of author role can see post IDs, while a user of subscriber role cannot.

You can find a brief description in Japanese on a book Introduction to PHP for WordPress Users. (written in Japanese.)

I want to see IDs when the mouse pointer is out.

If you use Version 2.0, you can see IDs without rollover. If you use Version 1.0, please update.

2.5

fix for notice when in trash.

2.4

span class="wp-ui-text-primary" added. For more readability.

2.3

indent and spacing fix

2.2

add prefix for function name

2.1

update donation link

2.0

media/user IDs are shown. IDs are shown without rollover.

1.0

post/page/category/tag/comment IDs are shown.