Remi Corson

This plugin helps admins to easily create admin notification inside the WordPress administration.
You can choose many options and decide how and where to display the notifications.

Easy Admin Notification

Tested up to 3.3.1 Stable Tag: 1.4 Adds the ability to create easily notification in the admin panel

Șerban

On every single post, older than 1 year (365 days), you may add a custom formatted text, in order to let your readers 
know the information included might be outdated.

Old Post Warning

This plugin will display a custom notification on every single post older than 1 year (365 days).

Easy Admin Notification vs Old Post Warning