So I came across this app and it is open source and wondering how secure it is. Read some mixed reviews on it considering its use of ZRTP ( http://security.stackexchange.com/questions/39440/is-redphone-a-secure-and-secret-way-to-communicate ) ... Does anyone know much about redphone??
i know of activists who use it to contact each other. so it must at least have a good reputation. it appears to be fairly user-friendly as well. open source is always good too. i don't know about how secure its methods of encryption are though.