Download XChat from App Store
Search for XChat in the App Store and make sure the developer is listed as X Corp. That is the official app, and from there you can pre-order or download it.
The download itself is simple, but one requirement is easy to miss: XChat needs iOS 26.0 or later. If your iPhone is on an older version, the listing may still appear, but installation will fail with an incompatibility warning. Before you try, it is worth checking Settings, General, Software Update first.
You will also need an X account to sign in after installation. If you do not already have one, you can create it inside the app. Not requiring a phone number is one of the more notable ways XChat differs from apps like WhatsApp.
Confirmed Facts
Developer: X Corp., which is the official listing to look for
Supports both iPhone and iPad
Requires iOS or iPadOS 26.0 or later
Signing in requires an X account rather than a phone number
Not Yet Confirmed
Download numbers and user-scale metrics have not been published yet