Hi @Adriano Faria your app is working as expected, but i found one problem.
Have you forgotten Declined state ?
Actually, if you invite someone, if he register and finally when on validating period, he cancel his account...
In invit system, the line isn't dropped or state changed to declined.
But marked as Converted with a link to "Guest Profil" that didn't exist,
Same problem occur on last invited widget
Otherwise, it's a great plugin, so nice work.
I'm working to create a conversion script from old plugin by another developer.