In today's game it came up that combat start so I cast shield and flew towards combat. In the next round I wanted to cast enlarge person which is 1 round, however I was already flying. Clearly I wasn't able to spend an action to move if I was going to still cast the spell, but under the fly skill there is no mention as to the action cost of hover. Since all other movement options clearly require movement and are thus part of an action with movement.
Also, in case it matters, I was not under the effect of a fly spell, but magical insect wings which acts like part of my body.