I think they even halted the development of the new bitcointalk forum that's supposed to be a lot more modern(with responsive css and such), so an app is probably out of the picture for a while unfortunately.
Unfortunately there is none.
There were a few unofficial ones but they stopped working after theymos implemented the captcha on the login page. But I was thinking, and now that there is a link that bypasses that captcha for your account, someone could update/develop a new (and better) app.
If there was one that was working though, I wouldn't really suggest using it(an unofficial app) if it isn't open source, as we wouldn't know what data they're collecting as they would have access to your email and your password, which is something you would really wouldn't want.