twicli を Rambox で使う ref: https://qiita.com/watagashi/items/6a1d1e92b9ba9e9ec38e

custom_code.js

const ramboxOriginalTitle = document.title;
function ramboxUpdateTitle() {
  document.title = `${
    document.querySelectorAll('#reply.new, #direct.new').length > 0
      ? '(\u2022) '
      : ''
  }${ramboxOriginalTitle}`;
}
registerPlugin({
  newMessageElement: ramboxUpdateTitle,
  newDM: ramboxUpdateTitle,
  switchTo: ramboxUpdateTitle
});