The One Bus Away mobile application is used by thousands of Seattle area commuters each day to determine if their bus will arrive on time.

But the award-winning app, developed as an open source project at the University of Washington by Brian Ferris and Kari Watkins, is now getting a little competition in its backyard.

New York-based Roadify just announced the launch of its free iPhone application in Seattle, which like One Bus Away tells riders when their bus is scheduled to arrive, and whether the bus is delayed.

Though headquartered in New York, Roadify’s lead developer is Seattle resident Ethan Arutunian. And Shane Atchison, founder of Seattle digital agency Zaaz, is an investor.

I’ve been playing with the app tonight, and the design is slick though it does not utilize the map-based interface of One Bus Away. (Which may appeal to some).

Roadify also incorporates the Twitter stream which means you can get real-time reports on a route-by-route basis with additional information from riders and transit agencies. (For example, I learned that the West Seattle Water Taxi does not run on President’s Day).

“Our front-end design makes it super easy for users on the go to find what they need in just a few taps, even if their journey involves several transport modes, such as transferring from suburban rail to city subway or from a ferry to a bus,” said Roadify COO Scott Kolber in a statement. “They can use the same familiar Roadify app when traveling to a new city, without having to download new apps or maps. ”

The app, which is free to download, is also available for New York and San Francisco.

UPDATE: Roadify’s Kolber offered a few more details about the Roadify app, and he tells GeekWire that they have a tremendous amount of respect for the One Bus Away app. But he noted that Roadify is different in many aspects.

He notes:

1. We’re a multi-mode, multi-market platform—bus, ferry, train, subway, etc– that can scale globally based on the architecture that Ethan has developed for us.

2. As you note, we combine official arrival/schedule data with crowdsourced content from Twitter and directly from our users. That’s a big differentiator, especially since some of the official content comes in the form of Twitter alerts as it does in Seattle and on other systems such as CalTrain, Long Island Railroad, MetroNorth (in NY) and elsewhere.

3. We’re focused on condition reporting, not so much on trip planning- maybe not a big difference from One Bus Away, but complementary to HopStop and others for example. This focus allows us to address the daily, chronic pain of hundreds of millions of mass transit commuters rather than occasional riders.

Kolber also tells me that the app can be shifted to a map mode, as you can see in the image to the right.