We launched AirTube as a beta because we wanted everyone to get their hands on it as soon as possible, gather feedback and work on new features from there. Now it appears there wasn't that much feedback, or many downloads for that matter ;). In hindsight, AirTube in its current form is probably too specific and doesn't meet the requirements of what a lot of you are after.
So, we've decided to stop the beta and start from scratch with ideas that will make the app more appealing.
First of all: thanks so much for your support! Second: don't worry! Because we based our "website parsing" on quvi, development on that continues and you will be able to keep using AirTube like you're used to and even add support for new video websites.
If you want to try AirTube in its current form, or want to re-download it. You can get the latest version here.