Jack Dorsey, the co-founder of the social networking platform Twitter, is progressing with Bluesky — a decentralized Twitter alternative — as its mobile application enters private beta testing.

Bluesky has hit the Apple app store as an invite-only app, allowing certain persons to try out the new social experience by creating an account via an invite code.

According to a report by TechCrunch, the Bluesky iOS app debuted on Feb. 17, amassing about 2,000 installs as of Feb. 28. The app is reportedly not yet available for Android testers on Google Play.

On Bluesky’s app store preview, the rival app looks very much like Twitter, with the interface having a lot of Twitter-like features, including how handles, followers, posts and replies are presented. In a similar style to Twitter, the Bluesky app’s feed also has likes, comments and reposts.

According to TechCrunch, the app allows users to create a post of up to 265 characters or just fewer than Twitter’s 280 characters. Instead of Twitter’s “What’s happening?” Bluesky asks, “What’s up?” Bluesky users can share, mute and block accounts, while more advanced tools, like adding them to lists, are not yet available.

Despite resembling Twitter so much, Bluesky is set to have some technical features designed to make it very different from Elon Musk’s social media giant. The platform aims to provide a decentralized social network protocol, which is expected to make its user data free from influence by any government or corporation.

Bluesky is built on the AT protocol, a new federated social network that integrates ideas from the latest decentralized technologies. Originally known as the authenticated transfer protocol, or ADX, the AT protocol is Bluesky’s main effort to enable a new way for servers to communicate with each other, allowing individuals and businesses to self-host and have multiple websites instead of one.

Related: Web3 communication app goes after Twitter with $12.5M seed funding

As previously reported, Bluesky released its first batch of code in early May 2022, a few weeks before Dorsey exited Twitter’s board of directors. In October, officially introduced the Bluesky social app and the AT protocol, which came nearly three years after Dorsey launched the project with support from Twitter in 2019.

While Bluesky has been moving forward with beta testing, Twitter has encountered some issues recently. On March 1, Twitter suffered another notable outage as thousands of users flagged issues with Musk’s social media platform. The issue was slowly resolved over a five hour period.

The news comes amid Dorsey reportedly moving some Bitcoin (BTC) using his other social protocol, Nostr. Damus, the first mobile app to leverage the protocol, was published on the app store in February 2023.