Signal is the best. Get it here. Don’t take just our word for it, here are a few cleverer people who think it’s the bee’s knees.
I am regularly impressed with the thought and care put into both the security and the usability of this app. It’s my first choice for an encrypted conversation.
— Bruce Schneier, internationally renowned security technologist
Signal uses your existing phone number and contacts list so it’s a doddle to use. It’s also free.
You have a responsibility to the people you communicate with. [subpoena thing here as evidence that they don’t hold much information anyway]