Make browser upper & lower bars disappear?

When viewing an image on an Android phone, the upper & lower browser bars (url bar, etc) remain visible, shrinking the image quite a bit.

Is there a way to make the image go fullscreen, without the browser stuff?

Also, is there a way to zoom in on an image? Pinch zoom, or at least a double tap? I have the plugin set to shrink the image to the screen size (“Shrink large images to fit smaller screens”), because otherwise many are way too big, but you should be able to zoom in.

Thanks for any help.