The real question is not why, but why not?

(I've been meaning to do this for a while but I'm still awaiting delivery of my round tuit, so thank you to the submitter.)

On Android too, if you use the browser on Android, you can interact with Hacker News same as usual, login, vote, etc. But you'll find yourself zooming and panning a lot. The rest of this comment is off topic: Speaking of voting, here are two people asking about voting at Hacker News, but yesterday was an election in Illinois with Obama's old senate seat at stake, and not one of about two dozen co-workers I talked to bothered to vote. There's more interest in voting for a Hacker News article than for a US Senator?