This is very small plugin made on demand to create a one setting page . where 

(1) Checked whether user-validation-by-email and user-validation-byadmin plugin are enabled or not.

(2) in setting page admin can choose either of them or none, depending on his requirement.

(3) For multi-admin website , one of the admin can be set as the responsible for joining process. i.e his email Id will be used as From address instead of site-emailID.

God know whether it can be of any use to you. but It can be good learning tool , where you want one master plugin to control other plugins.