I'm building Thread - an ad-free, private social network for groups. It's an alternative to Facebook (Messenger and WhatsApp), iMessage and GroupMe. It's the best way to connect with, share content to, and interact with the people in your life.
It's a limited release right now (still in alpha), but please sign up and check it out at https://thread-app.com/register. EDIT: it only is available on desktop web at the moment to US based users. Anything else will most likely give you an error.
E2E encryption is something we are considering building. Right now, the promise is no-ads, no front-end tracking, and no selling data to third parties.
Happy to chat more about it and answer any questions (maybe this isn't an appropriate place for that discussion).
Minor bit of very biased feedback – the name "Thread" is quite overloaded. Thread (my employer) is a clothing recommendation service, ThreadsStyling is a luxury fashion concierge, Thread Group are an IoT specification, Open Thread is an implementation of that spec I believe.
Are you using ActivityPub &c?
Even if it is somewhat bulky, these linked data standards are the way to ensure you are creating the most open, reusable data possible on the largest stage.