The current 'logged out' view in a perspective app has bad accessibility. After logging out of a perspective app you land on a page that looks a like this:
The back button on the page isn't actually a <button> element but an <a> tag. If the <a> tag used an href attribute it would be possible to tab to the element and cause the navigation, but it doesn't, so there's currently no way of 'pressing' the back button on said page using just the keyboard. Refreshing by hitting F5 obviously works because you then land on the login screen but it would also be nice and not particularly difficult to add a tabIndex attribute to the <a> tag.