[_frog]

The iOS convention is to put close / back buttons on the upper left, primarily since most apps have new screens enter from the right. I guess that trumped the precedent set on the web.

[foz]

I see what you are saying, but the cards as presented don't really reference the iOS UI. Maybe I'm just too used to the web app.

[_frog]

I'd argue they still do, it's just a modal view with a different animation, thus it makes sense to follow those conventions.

Also in the web app I tend to just click on the background to close a card.