Apple Watch will unlock your hotel room door, guide you home and more: the app roundup

You're at the Westin Grand in Berlin having a luxurious vacation. After finishing a delicious bowl of mushroom consommé -- chanterelles are in season, after all -- you stroll up the lavish center staircase toward your room. Having left wallets in the past, you simply hover your Apple Watch over the door. "Click!" And that's that. Magnetic plastic cards are so uncivilized.

This is the future Apple imagines for you with its new Watch, and it's working with Starwood Hotels (the group that owns Westin, among others) to make that future a reality. And that's just one of several scenarios for Apple Watch that were introduced by Apple VP Kevin Lynch during a third-party app demo on stage in Cupertino, California.

Beyond Starwood, American Airlines is also working on Apple Watch -- both are using WatchKit, the software toolkit Apple built for third-party app development. The specific context wasn't given for its use with American, but one can easily imagine using Apple Watch as your electronic boarding pass.

City Mapper, a popular transit app on mobile, is getting an Apple Watch version, as are home-automation apps from Lutron and Honeywell. BMW is apparently creating a tool for finding your car with the Watch. These are the "internet of things" applications for Apple Watch -- home automation, location guidance, personal-object retrieval, etc.

And then, of course, there's stuff like Twitter and Pinterest. Twitter is relatively fully featured from the looks of the brief demo shown: You can tweet from it, as well as browse your timeline and such. Pinterest acts more like a reminder list, letting you know when you're physically close to something you've pinned.

We'll assuredly hear more about Apple Watch apps as the trio of watches launch sometime in early 2015. And hey, maybe you're making a really cool app? Or you know of one that's in the works? Don't hesitate to let us know!