Are there plans for an iOS app for Fluther?

No.
Fluther is no longer being actively developed (as far as I know).
There was an app from a third party but that was several years ago now and even then it offered less functionality than the web page on safari.

There was an App on Apple’s iTunes, until about 7 years ago. Here’s the scoop on where and why it disappeared.

Welcome to the pool @MattJude !

I’m a UX designer, let’s do this!

I love your enthusiasm @Outthere. Message @Mariah, perhaps she can give you some pointers on whether it’s possible for you to be involved or not.