Because this is a third-party modification (a "tweak"), it is not available on the official App Store. It is typically installed as an on non-jailbroken devices or via a repository on jailbroken ones.

: Save videos from your feed and both images and videos from Stories directly to your device, often via a long-press.

: Locate the Wolf for Facebook IPA from a trusted community source like GitHub.

: Use a tool such as AltStore or Sideloadly to install the IPA onto your iPhone.