Board Admins can change the workflow for the board:
Note: the Backlog, Done and Trash columns are special: they can be hidden from view (by clicking on the green eye button), but they cannot be renamed, moved, or removed.
Check out this video on customizing workflows for boards.
Board Admins decide who is part of the board team:
Check out this video on people and roles in Kerika.
Board Admins can permanently remove items from the board's Trash. This sounds trivial, but it's actually significant :-)
This simple mechanism provides a safety net for the entire team, by making deletion of cards a two-step process!
Usually, there is just one Board Admin: the person who created the board in the first place.
But it is possible for a board to have several Admins: anyone who is currently a Board Admin can upgrade any other Team Member or Visitor to the role of Board Admin. And, of course, so can Account Owner.