For me and my friends it was Google Plus before they leaned super hard into the material design. They did it twice too, changed it up over and over. We definitely felt there was a golden age though. The circles feature was awesome and loved that we could Instant Message each other straight from there, go into a group chat, then into a voice/video chat too. https://youtu.be/QnANHd_kqBQ?si=xOsrqLsNWuKBg5qF