What if you isolate only the tweets with images from your twitter feed? I find there are a ton of great posts I would have otherwise overlooked when scanning my feed like this. Also check it out on ProductHunt: http://www.producthunt.com/posts/picfeed
Maybe you should have worked a bit on the landing page. Maybe the background - with a bit of a blur - to have a glimpse of how the app really looks like - or at least some description.
good point, I put one up now.