I have a multi-site, can I use your plugin ?

Not right now... At least not optimal.

Using the plugin probably won't break your site, but it might not work as expected outside of the main site.

The registration process in a multi-site is different than a 'normal' installation, due to the nature of the setup of a network and how users (in the main sites) are assigned to 'sub sites'.

You can activate the plugin, you will see a warning, which you can ignore if you wanna test it out. We are working on a proper integration for multi-sites but no promises on eta.