I came from a zero programming background and built the website in Ruby on Rails whilst learning Ruby.
I wanted to build a fully native app for the best user experience and really enjoyed learning ruby, Rubymotion seemed like the perfect fit and it didn't disappoint.
I still have the limitation with Android of course...
When you log in initially you are following 'Footpoll'. The main page is similar to twitter dependent on who you are following. You can go to the categories section to view Man Utd polls.
Happy to write an article on that. I initially built the website using Ruby on Rails and had twitter/facebook omniauth implemented.
It was then a simple case of displaying a web view in the app with login similar to how you would on the web, then diverting back to the app upon login.
I think a few have tried but nothing major I don't think. I recall a site called Opinsy a year or so back.
My initial thoughts we're creating it on a subject I was passionate about, as I personally wouldn't go on a generalist site to argue my opinion's about chalk then about cheese.
But the concept can be applied to anything of course.