As asked.
Not exactly a Fluther app but…
There used to be a Fluther app that was basically UIWebView of the mobile site. It slowly broke and was discontinued.
It was pretty horrible.
The mobile version is way better than the app ever was.
Mobile site
I have the fluther app, but only because I had synced an old iPhone with my new one and was able to transfer it over. It has a few kinks but it works for the most part.