A new Glassware app called Preview allows Google Glass users to view a movie’s trailer just by looking at a movie poster. After the app is manually installed, if a Glass wearer looks at a poster, the film’s preview will automatically play from YouTube. The app was created by Takahiro Horikawa, who debuted the software in January, and has been making minor fixes since then. The idea behind the app is to allow users to go to a movie theater, view trailers, and then decide which film to see.

“Preview for Glass is a future application for Google Glass that changes your movie life,” suggests the product’s site. “With Preview, when you go to the theater and look for a good movie, you don’t need to take your smartphone out and type a movie title in search box to see if you are interested in it. Preview allows you to watch a movie trailer instantly by just looking at a movie poster.”

If a user is viewing a trailer, and then looks at another poster, the app will automatically recognize this and begin to play the new movie’s trailer. The goal is to regularly update the database, so viewers will always be able to view trailers based on any poster.

“I love the idea behind this although there’s just one thing I might suggest for a future version: The ability to screencast the trailer or send a link to it from Glass to a nearby smartphone,” writes Kevin Tofel for GigaOM. “That way instead of just one person with Glass figuring out which movie to watch, a group could do the same.”

Preview officially left beta status last week. The GigaOM post includes a 3-minute video demo.