Mover is a plugin for Vue that lets you import Poser animations. It also allows you to import dynamic hair and cloth. Without Mover, Vue can import Poser files, but not the dynamic hair.

Vue is very easy to use. Easier to learn than Poser, IMO. Very intuitive. Though if you want Mover, you might consider getting Vue Infinite instead. Mover is included in that, along with lots of other cool stuff.

However, you may be better off simply learning how to use Poser 5 properly. You should be able to get very usable results from it. If you're having trouble, post your render or a screenshot of the problem and ask. People here will be happy to help you.