Found one from 2011. As evident by the lack of a mobile app you can see how the idea was received then.
http://www.finchforum.com/viewtopic.php?f=10&t=14867
That being said I quite agree with you. The site is loadable and works completely fine from a phone. However, it is a horrible pain to zoom in each time a page loads to read something. I don't want to have to scroll back and forth as well as up and down so I enlarge the text just enough to block out the extra space on the side. After a few minutes of reading threads my head starts to hurt and then I have to put it down and go do something else.
Not to mention trying to click on some of the links without blowing it up super huge. If I try to select a page number in a thread it's always a race for me to hit the right one before the page loads the incorrect one because I fat finger the screen.
Honestly I don't know what it would take in order for a Finch Forum App to come into existence but I for one would enjoy and use it. I do not know if the owner of the site has ever considered doing it though.
