After seeing your comments in this thread and looking at your comment history, I have to ask: What is your affiliation with Signal/Open Whisper Systems, if any?
Just very enthusiastic about Signal then, I guess?
Often when someone is so outspoken about a product it's because they have a vested interest in its success (and they don't always disclose that fact)... that's why I asked. Thanks.
More enthusiastic about privacy and free software. I often see worse apps recommended for privacy reasons, so why not bring up the flaws in those and what's better about this. If something better comes along I'll switch to that and recommend that instead.