Wordpress Videos Plugin - Question re usage

Hi
If I install WordPress and a theme for my clients am I "allowed" to install the Integrated Video Tutorial plugin on "their" sites too? Or is it only available for my own sites?
If the answer is "yes" what are the implications of this further down the line if, for example, I cancelled my membership - would they lose access to the videos? Or access retained but no updates etc etc

Thanks in advance & sorry if this isn't the right place to ask the question