Signal is wannabe private because of phone number, metadata and contacts mining (even though they say they don’t, they can). Simplex looks promising and the guy is headed in the right direction. As soon as he makes it that the servers cannot correlate which IP is talking to which IP, I will say they are a really good solution. Telling people to use Tor with your app for privacy is not a solution.

Besides that, it is a very well made app that has a nice UI and works very well. Also many good features.