I don't know much about this mastodon api client yet, but it sure looks cute. Lots of fun, exaggerated animations.
mastodonapp
A new iOS / MacOS mastodon client has recently been released to the App Store - Manfred. @manfred_app Seems to work for GoToSocial instances, too. Free for now.
https://apps.apple.com/us/app/manfred-mastodon-client/id1667817813