Naven
Glossary
Presence
Whether somebody is currently available.
Online, away, in a call, last seen at a time. It is the most privacy-sensitive of the small signals, because it describes a person's day rather than a message — a last-seen timestamp reveals sleep patterns to anybody watching it.
Granularity is the design lever: "active recently" says enough without saying exactly when.
Where Naven stands
Naven shows presence in conversations you are already in. There is no way to watch somebody you do not talk to, because there is no directory to find them in.