Signal
Used by 24 peoplesignal.org ↗

“If there's one piece of software I use more than any other, it's probably Signal.”
Thursday Bram Interview, Writer · via Uses This 
“Although people message me on all of these apps, as well as by text, for confidential messaging, I use Signal.”
Warren Binford Interview, Law professor, pediatrics professor · via Uses This 
“My default messaging app is Signal, because I care quite a bit about security.”
Alex Gaynor Interview, Software developer · via Uses This 
“Signal for top secret group texts, e.g.”
Helen Shewolfe Tseng Interview, Artist, designer, wolf witch · via Uses This