I like HN the way it is, only if I could vote on iPad (or worse, on iPhone) without having to zoom 600% in first. Those up/down arrows being so close to each other drives me crazy.
No, I have no knowledge of its existence. It looks good - I'll try it for a few days.
It might be good to submit it as a new link... I'm sure it's been posted before (though I'd never seen it), I'm sure there are many HNers who don't know about it and it might be useful for them (for iOS, there are a few nice applications; but on other platforms, I think there might be none and this web app could be a life-saver for many!)
Yes, I have it and it's very good and pretty. But I just can't possibly live without a chronological list of submissions (like http://hckrnews.com/) so right now that app just sits in my first home screen and I never use it!