I downloaded the application on Mac before 2.0 and the webapp and it isn't updating. I can't seem to download a new version or update the existing app I have: is it no longer supported?

Unfortunately, yes. I sent out a project update a while ago, but unfortunately I don't have the time or resources to support a desktop version and still be able to add all the features I want within a reasonable timeframe. Later in the project I might take a look at adding desktop support back in