Yes that's 100% coming, we just need a bit more time to get it right.
We launched a feature in the web app where you can download your prototype as a ZIP containing html/css/js to run offline but we really want to have offline in-browser working for everyone
In my comment I was more referring to the iPhone app side of things as that's my typical use case. I noticed that I need an active connection to do pretty much anything.
This is definitely something we have planned, our main aim was just to get this version released (it was a long painful road) but the next step is sorting out its offline capabilities
We launched a feature in the web app where you can download your prototype as a ZIP containing html/css/js to run offline but we really want to have offline in-browser working for everyone