bsky.app/profile/iceb... Apple stores which devices/users install which apps. They have the device IDs. US government could obtain a list of people who installed the app if a court authorized it. Not clear what they mean by having to storing device IDs. Those IDs aren't accessible to Android apps.

Sorry, there will not be an Android version because there is no way to provide 100% anonymity. Each person's device ID would have to be stored and that information becomes discoverable should the government issue a subpoena. Only iOS made this possible and completely protects the users.