For those impatiently interested in something like this, checkout - http://bodylog.com/

But where is the app download link, or place to sign up?

Yet to launch, you should hit 'Sign me up' towards end of the page at http://bodshots.herokuapp.com/ and we'll let you know when we do. We're considering a name change as 'bodshots' really comes bad in google search (specially image search) :P

How many users does your app have?

We haven't released to public yet, still counting sign-ups.