Awesome...lots of useful intel here. Please do update when you have some more results. Intuitively, I'm thinking a mix of as few words as possible to convey the use/value because I'm only going to give you about 5 secs of attention span. So at that point, I am either leaving or I want to know a little more, so there is where it gets interesting on how much and what kind of things produce the best results..maybe also a testimonial or two to build confidence.
Its not an app, but check out the www.theleanstartup.com I like how its rich with info in just the right places, then it draws you in deeper. Thanks for the info.