The tool gives a quick opportunity to go through all content items in the tree and republish them. It's especially useful during development and when syncing with staging/production environment.
The tool is published to github and for the time being it gives an administrator a possibility to go through all the pages and re-publish them.
It's quite useful ex. with search solution by Jeroen here (with some updates), since normally, a standard search is added in a later phase of the project, once there is more content to be searched for. When content is published, the content events will be triggered, so the SearchText (in this example) would be recalculated. It goes well with content publishing/published events.
For me, it was quite useful for filling in the custom DB that depended on content items that were previously published. To add your own logic, replace:
// this is the place where you do "something" // with each of the content items you are iterating through
Hope you'll find it useful, too!