Custom Forms for All Users

I would like you create a simple form (text fields, password, drop downs, etc) for all of my Multisite clients to fill out. Is there a plugin that I should be using to create this?

Please keep in mind that I don't want this to be on the front end of any of the sites that I own or manage. This is solely to be in the backend of my installation for me to manage and control - and for the clients to fill out and edit. That's it.