To begin with, it's streamlining its QR code approach: you now need just a single scan for the conversation, and the code only includes the safety numbers instead of the phone numbers. That prevents people from inadvertently revealing phone numbers and potentially exposing the conversation. Would-be snoops who already know someone's digital fingerprint will recognize who you're talking to, but they won't read the chats themselves.

Also, new devices and app reinstalls won't always require that you approve someone again to keep the chat going. The latest Signal version has an optional "advisory mode" that will tell you when safety numbers have changed, but doesn't preclude you from talking to the other participant. It's turned off by default, but OWS may enable it by default for new installations if it works well.

The changes might be coming just in time. OWS tells American Public Radio's Marketplace that demand for the app jumped a whopping 400 percent after Donald Trump won the US presidential election. If you ask co-founder Moxie Marlinspike, the interest comes from people who are "less comfortable" with Trump having control of the US' far-reaching surveillance apparatus. In other words, they're worried that the President-elect might abuse his power to spy on critics. Is that rational? Not really (there are still some anti-abuse mechanisms in place), but that won't stop nervous internet users.