TON - Telegram Open Network. Blockchain-based technologies that also included the cryptocurrency called Gram, but is way more than just the cryptomoney. I highly recommend reading the "technical paper" if you have time and technical understanding. It's absolutely fascinating (was written by Pavel's genious brother)!

Durov decided to develop it and got billions of euros for that. It had some delays, but otherwise looked ready.

But then USA came in and said using jaw-dropping argumentation and forbid Telegram from running it ANYWHERE in the world!.. So Durov had to officially abandon the project.

Currently TON is still being developed by non-Telegram teams.