I have recently switched from the POS (too fragile and battery life becomes worse with each new iOS update) iPhone 5 to Nokia Lumia 920 and the only app I'm missing is the Twitch.tv app... You should definitely consider it, or at least make it possible to watch the streams directly at streamer's web page without using Flash plug-in (same way I can watch YouTube videos directly, without using any apps).
It would be amazing to see better chat support to. I also have iPhone and it is extremely horrible with video and chat. I hate using amdroid and iPhone with it. Also design a streamer that can support phone hook up and allow streaming of phone game play. Because lots of new games on mobile devices
I started looked at trying to develop a Windows Phone 8 app for Twitch since I've just finished Uni and started looking for a job and we're not sure if they've started developing one yet.
Main issue I have is that Twitch don't openly give the RTMP address of streams out (and rightly so), so at the minute all I've started to do is create a mock-up app and being to integrate the Twitch API for searching for streams etc.
First mock-up is http://imgur.com/Ghh6ng7
Hopefully Twitch come out with an app before I make a ton of progress however.
I am a loyal (i sub 2 channels and watch at least one a day, if not both) Twich subscriber, and i am literally willing to pay for a good WP8 app. I love twich, and i love my phone OS more. Please, i already do my best to give money to the people that earned it, and i am willing to give you more if you will give us users what we desire.
I would also love to have a twitch tv app for windows phones. I agree with twitch that the last years it wouldn't really have been beneficial for them at all since no one basically was using windows on a mobile device, but times have changed and now thes have kinda catched up in terms of numbers.
Since the app is free in the google play store, I don't think it'd be necessary to make it cost something. On the other hand, if twitch only decides to implement the app to the windows store at a cost of some dollars, I'd also approve of it.
I'm putting my name on this, as a former android user, I used the twitch ape quite often while on the move. Really find myself missing it more and more since moving over to windows phone 8. Please, consider doing this soon!
Twitch is my favourite app. It completely replaced TV in my home in that short time I have a break during a day. Please consider to have your app everywhere possible: windows phone, smart tv, apple tv.. There is no strong online tv vendor, You have the potencial, but you have to work hard to meet expectations. Good luck