You can get a app for iPad and they might have it for iPhone/Androis also. But It's called "Forum Runner" and it cost $1.99 USD for iPad that is. And it helps you view the forums easier on your mobile devices. But a app for the site it self I think your out of luck....for right now that is.
I really wish there was an App at the app store. I would like to see submissions, posts and get a notification when a design submission has been rated. It's so frustrating.
I know that the only way to really achieve this some what is to have a designated folder in your email and direct all DC emails to that folder. And then when your out with your mobile device you should get a email saying that you design was rated or commented on. But you have to have your email setup with your phone. I do it with my iPad and I hear a ding noise when I get a email. I hope this helps.