Telegram
Visit the official website.
In 2015, the Plag community was faced with a challenge: Plag strongly encouraged random encounters on the site, making it difficult (and fun!) to send a message to a specific person. Users would create "inbox" posts and add them to their biography, so other people could comment on them. Many users ended up creating alternative groups on Telegram, a small messenger app that was claiming end-to-end encryption, with open source clients and a publicly-documented protocol.
Telegram was growing rapidly and was becoming famous for police institutions the world over complaining about not being able to view messages. Every year, Telegram would add features no other messenger came close to—basic Markdown syntax, a strong bot ecosystem, custom stickers, even in-chat games!
In 2016, I joined the group of volunteers who translate the Telegram application to French. I became a moderator of the official French group, and later, of the official Japanese group as well. Although I am not very active nowadays, I still have these roles.
As of 2024, Telegram is the most popular free application on the Play Store in France (excluding games), in front of TikTok (2nd) and WhatsApp (3rd), and sits comfortably in hall of fame of apps with more than a billion downloads.