nostr:npub180cvv07tjdrrgpa0j7j7tmnyl2yr6yr7l8j4s3evf6u64th6gkwsyjh6w6
some history:
https://en.wikipedia.org/wiki/Open_Whisper_Systems
yes, TextSecure was part of it, so was RedPhone
i used RedPhone back in 2013, i didn't know anything about TextSecure