Redmine contains a very powerful instrument - hooks - which are widely used by plugins for adding custom content to pages. That is if developers want to add e.g. Google Ads to Redmine pages most likely they will choose hooks to do this.
The problem with hooks is that you need to be a developer to use them - you need to be familiar with Ruby, Rails, eRuby... This is where this plugins helps! No, it does not teach you to develop... It makes it possible for end users to use Redmine hooks for placing custom HTML content on Redmine pages by providing a nice and easy interface to hooks.
Author: Andriy Lesyuk
Google Ads for Redmine
This plugins provides a nice interface to Redmine hooks. With this interface any user can define his/her own HTML code to be placed on Redmine pages. The interface contains a nice thumbnails showing where the content is to be placed.