This plugin allows you to mark a job a favorite. This is controlled via a list view column you need to add to a view. You can then click on a star to favorite or unfavorite a job. There is also a job filter to allow you to create a view that only shows your favorites.
It is recommended you change your default view to either one you create, or follow the directions in Editing or Replacing the All View to allow the Favorite column to show up. Once you have the Favorite column, it will show a star that logged in users will be able to click to make a favorite. You can also add another view, and apply the "Favorites Filter" to show favorites only in that view.