I saved this when you initially posted it but now I have so much saved junk its very difficult to find. I have some (good) thoughts but I need to come back for that. Will update this post when I get a chance. This is very cool.
Also, no idea how you’ve done it but your website is completely unscrapped by webcrawlers. Even searching for the exact title of this post doesn’t return any results on DDG, Bing, or the evil empire. Well done.
Yes it uses your phone number. You now have the option to use a username though.
Personally, while I totally understand the criticism, this is not an attack vector I am concerned with. I want a private messenger that hides the content and metadata of my messages from ad companies, spying neighbors, and the government. Signal does all of this.