I can't find Folio in the 'Open in...' menu

We've had a number of users comment that they can't locate Folio in the 'Open in...' context menus for a PDF document.

The reason for this appears to be an iOS imposed limitation of only showing a fixed number (10 last we checked) of applications capable of opening a particular document type.

To fix this problem, the only solution currently seems to be deleting some of the applications shown in the 'Open in...' menu until there are few enough that Folio shows up in the context menu.