Ruby Flog
Ruby Flog is a Visual Studio Code plug-in that runs flog locally against your code and displays relevant metrics in the status bar.
By default, Ruby Flog displays the average flog per method in the selected file. Or, you can select some text and Ruby Flog will display the total flog for the selected text. This is handy when you want to see if your refactoring had an effect on a method's flog.
You can find Ruby Flog on the VS Code Marketplace and on GitHub.