MiniGroup – Instant Private Groups for Work or Fun
https://www.minigroup.com/

Minigroup is a completely private platform that lets you share the right stuff with the right people, without intrusion from strangers, friends-of-friends, or search engines, all from a single account. Use custom identities to share appropriate personal information with various groups. Features include: 1) Private and secure, by default and design; 2) Easy, lightweight, and flexible; and 3) Share from anywhere to anyone. This has been added to the tools section of Research Resources Subject Tracer™ Information Blog. This will be added to Privacy Resources Subject Tracer™.