When I look at your homepage I'm thinking "So I have to enter in _more_ titles/descriptions of photos I've (probably) already uploaded to other sites like FB/Flickr?" Maybe I'm just lazy, but that doesn't appeal to me, especially if I'd have to do it on my phone. That said, I'm also not an avid photographer, so I wouldn't really be a user of the app anyway.
You could also try services like http://betali.st or http://betabait.com/ to find beta users.