I think that Buildwithme is instead an excellent website, with a good usability and it's one of the few websites that tries to break the taboo of "making an app

I think that Buildwithme is instead an excellent website, with a good usability and it's one of the few websites that tries to break the taboo of "making an app of a webapp". And I think it delivers pretty well. Of course, it's not possible with all the webapps (and not suggested). On the other side, I think it's a very different problem, and I'd advise to not mix things up: there's style, there's identity, there are UI canons. Bultwithme for example mixes web+mac UI canons, has a mac style and doesn't work a lot on identity. Take Nike.com to have another example. It uses a web style, a bit toward the app format, with UI canons that are almost everywhere app-like... but it has a very strong identity. On the other side, take Lightroom. It's obviously an app and uses desktop UI canon... but it has a definite identity that you can't mix up with anything else. Also dropbox, as you cited, uses a quite standard web style and web UI canon, but it has a strong identity. Don't reduce the identity to the UI canons or interaction styles: they are very different things. ;)