Hi, while we're in beta we've been keeping things to Chrome only, as it lets us progress the product faster at this early stage. Specifically, this cuts out a lot of time spent on cross-browser testing and bug fixing and lets us focus on making sure we've got the right mix of features first.

It's the first time I've tried this approach myself, so it's a bit of an experiment, but I think it's been useful for this particular product. In saying that, we will be looking to offer wider browser support down the track, so stay tuned!