Please note an important detail about Vernissage for iOS: it is a dedicated client that connects ONLY to #Vernissage instances (while communication between servers is handled via ActivityPub).

It does not support Mastodon, Pixelfed, or other services. Vernissage uses a different, in some areas more extensive, API. Unfortunately, many Fediverse apps imitate Mastodon by exposing the same API, which can lead users to believe that this is how the Fediverse works by default. 😉