v3.3.0

Yggdrasil now works on a phone -- as the public demo.

Added

• The public demo on your phone. Opening any Yggdrasil link on a phone takes you
  straight into the read-only demo, no account needed, on the page the link points to.
  Signing in and registering stay on computers and tablets; on a phone you are shown the
  demo instead of a sign-in form, and an invitation opened on a phone says to open it on a
  computer.
• Viewers that follow your fingers. On a phone one finger scrolls the page, even over
  an image, and two fingers pinch to zoom and drag to move it -- in the CBCT and MRI
  grids, the photographs, the panoramic, the 3D intraoral scans and the pathology slides.
• Drag a brain series onto a window with your finger, or tap the series and then the
  window it should open in.

Changed

• Pages laid out for a phone. The side menu opens from a button at the top and names
  each entry, including Home; patients are listed as cards you can tap anywhere; and the
  modality tabs and viewer controls stay at the top of the screen while you scroll.
• "Best viewed on a bigger screen" is now shown only to signed-in users on a phone,
  for the pages that still need a computer. Visitors and the demo no longer see it.

Fixed

• Administrators are notified of new registrations again. The notification email
  failed silently on every sign-up.