It looks like you are searching for a way to install or use a modified version of (likely an IPA file for iOS) from a source called AppsMe , or you're comparing it to the official app.

allow for features like message scheduling, hiding "last seen" status more selectively, and disabling read receipts while still seeing others'. Older Device Support

They must use a (such as AltStore, Sideloadly, or Scarlet) to sign the IPA with a personal Apple ID certificate. This tricks the iPhone into thinking the app was developed by the user.

The baseline. Owned by Meta, end-to-end encrypted (E2EE) for personal chats, but rich in metadata collection. It requires a phone number and cloud backups (unless disabled). It is the most widely adopted messenger globally.