The following controls are available via the Navigation Bar at the top and via the keyboard:

Nav Bar ◀ and keyboard ⇐: Go to the previous image

Nav Bar ▶ and keyboard ⇒: Go to the next image

Keyboard 'home' or ⇑: Go to the first image

Keyboard 'end' or ⇓: Go to the last image

Nav Bar album icon: Go to the album overview page

Nav Bar slide show icon: Start the slide show and hide the nav bar (see also below)

Nav Bar Ⓜ icon (if shown): Show on the map the location the picture was taken

Nav Bar ⓘ icon (if shown): Show additional picture information

Mouse wheel: Zoom an image (when the slide show is not running)

Mouse: When in zoom you can drag the picture around

To stop a slide show and bring the nav bar back: Press the keyboard Space Bar or Esc key.