Show HN: Sunsetter - find out when the sun will set over there

I see Mount Fuji from my living room window, facing west, and I wanted to take a picture of the sun setting behind it, casting a nice V-shaped shadow, like this one: http://www.flickr.com/photos/w00kie/4161767317/

So I looked on internet for an app that could tell me when the sun would set in the right alignment, but all I could find were apps or website telling me WHERE the sun would set AT A GIVEN DATE, not the other way around. Scratching my own itch, I built this app.

Now I know if I want to take the same photo from Skytree, Tokyo's highest tower, I should go there early November: http://sunsetter.herokuapp.com/#pov=35.71,139.810744&poi...

Or you can use it to predict alignments like Manhattanhenge in other cities: http://w00kie.com/2012/07/15/predicting-manhattanhenge/