Google has put out a teaser and an invitation-only app for its new photosharing service, Photovine.

The service lets users contribute to a shared caption, creating an album around a single photo or thought. Take a photo, make a caption and see what your friends snap to fit that description. You can also, of course, see your friends’ albums and add your own photos.

Check out the teaser trailer here:

Off the top of my head, I can think of a couple really neat applications for this app. For one, it’s a spontaneous way to keep in touch with friends — essentially the photo version of a funny e-mail thread. You could make a caption based on an inside joke, for example, and watch as replies from your friends roll in to brighten your day. It’s similar to the idea of Google’s Hangouts on Google+, without the necessity of having everyone commit to connecting at the same time.

It would also be a great way to make plans and get recommendations. If you take a picture and caption it “My favorite cafe,”for example, your friends could then take pictures of their recommendations of neat places to go.

For some strange reason, the app is only available on the iPhone at the moment, rather than on Google’s own Android platform.

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