Jeff Waters made this product
VIPole works with an email address and they're currently working on making an annonymous entry. It's a cool app that protects your identity and all the information you share within is encrypted e2e. Plus they have useful features like wiping up history, editing, message auto-burn. Althought you dont need a phone number to register, you can still make calls with audio or video and make calls to other people who are not using the app. These communications are also fully encrypted even on server, which means no one can really track you.