The new app is the latest of many Twitter rivals to emerge following Elon Musk’s takeover of the social network, which has driven former Twitter users to return to older apps like Tumblr and try out other decentralized social networking services, like Mastodon. Several startups are also spinning up their own Twitter competitors as well, like T2 and Spill, which have been raising seed rounds.

But Damus is not a venture-backed startup. Instead, it’s another experiment in decentralized social networking. The app’s promise is an open social network without a central authority that makes decisions about the network’s content or who’s allowed to participate, as Facebook or Twitter do. Instead, explains the app’s homepage, “you are in control…there is no platform that can ban or censor you. You are in control of your data,” it reads.

The site also touts end-to-end encrypted messaging — something Twitter does not have, and which has concerned users in the wake of the Musk takeover. There’s also no requirement to sign up with a phone number, email, or name because of how the Nostr works. That’s a big point of differentiation with Mastodon, where a user’s account is attached to a particular server where admins have some control over their server’s registered users. That also means issues with the Mastodon server you’re using — like an outage — could impact your ability to use the network. And you could risk losing data if that shutdown was sudden or permanent.

On Damus, messages are distributed through decentralized relays — in fact, the name Nostr is an acronym for “Notes and Other Stuff Transmitted by Relays.” There aren’t federated servers involved, but some Nostr relays are said to be better for filtering out spam.

Above: a tweet from Nostr developer @fiatjaf

Bitcoin integration is also a part of the Damus experience, allowing users to tip friends’ posts, for instance. This is made possible by way of Bitcoin’s Lightning Network. Plus, unlike Twitter, posts can also exceed 280 characters in length.

According to Cointelegraph, Nostr’s early testers have included Ethereum co-founder Vitalik Buterin, whistleblower Edward Snowden and pro-crypto U.S. Senator Cynthia Lummis.

Damus’s decentralized nature presented a problem for getting through App Review at first, as Apple kept asking the app to follow the same rules as any other social network — like providing a way for users to flag objectionable content, and having a policy that makes it clear abuse is not allowed. The Damus Twitter account had earlier tweeted the app was being rejected repeatedly, despite its claims that it had resolved the issues Apple raised.

That changed yesterday, as the app was finally approved, Damus announced on Twitter. The account has 17.7K followers as of the time of writing — so even if all of Damus’ potential users were to leave Twitter, it wouldn’t make a major dent in Twitter’s user base. Still, Damus is only one of several Nostr projects in development, according to Nostr’s website.

Dorsey also celebrated the launch of the Damus app on Twitter, calling it “a milestone for open protocols.”

The former Twitter exec, however, has been busy building out Bluesky, another decentralized social network powered by a new AT protocol, poised to go live in a client app that will also resemble Twitter. Meanwhile, Mastodon — which has been growing in popularity following Musk’s acquisition — is using an older protocol called ActivityPub. Tumblr may also add support for ActivityPub, its owner said. Bluesky and Mastodon won’t be able to interact unless one chooses to integrate with the other’s protocol or some other system is devised. Damus adds yet another open protocol into this mix, making the new battle among Twitter rivals one that’s not necessarily about Silicon Valley startups but social networking’s technology foundations.

Damus developer William Casarin told us the new Nostr-powered app won’t be interoperable with Mastodon or Bluesky either, but “there could be bridges between these protocols” in the future.

Damus is on GitHub here as well as on the App Store. The app is now ranked at No. 10 in the iOS Social Networking in the U.S. It’s also in the Overall rankings in four countries: Hong Kong (9), Vanuatu (90), Singapore (91) and Macau (92).