GrabLog shows what packages can be updated and then shows changelogs for each package.
Package managers don't require changelogs to be a part of the metadata. Because of that, developers must seek these changelogs manually. It is very tedious: open the package manager's website, search for the package, find its repository, search for any changelog files, go to releases section to see a changelog.
GrabLog automates everything and gets you the package changelog in one click.
Note: this tool is only for fetching changelogs and displaying the latest version of a package. It does not update any packages by itself and does not modify any files in your project.