The Lumicall web site now offers free calling from this web site to any user with Lumicall.
This service is powered by WebRTC, a new standard for using a web browser as a telephone.
For your security, no plugin is required. Sites that do ask you to download third-party plugins add an extra element of risk as each and every plugin you install potentially contains new backdoors for gathering your personal data. Therefore, Lumicall has implemented this service in a plugin-free manner.