I applaud Fastmail for this move. The average internet user is not you or me on HN and they have no idea what Thunderbird is. So why not make it easier for people to switch from the Big Thee email accounts that invade your privacy to Fastmail? Most people do not see apps as things that do multiple things (Facebook app for Facebook, Gmail app for Gmail, etc..) so that is what they understand. So give them a Fastmail app for Fastmail even on the desktop, which provides more usefulness that the web version. I say yay.
Gmail, for instance has a way to store email offline via the web. Fastmail does not. The app aloows this functionality as far as I know. And it holds this data outside of your browser which I feel is more secure.
