Shows changes count of methods since the beginning of project history as a read-only text labels with information about changes count for a period of time and a histogram with changes count per day above the method's signature.
https://plugins.jetbrains.com/plugin/12564-topias
Just install plugin from official JetBrains repository, and it will find a VCS root in your Java project. If VCS root was not found, you could set it manually in plugin's settings (Settings -> Topias plugin settings).