At first – this plugin created for collect more and more new users applying referral system only by new token on blockchain.
This plugin is perfect for cryptocurrency, for new cryptocurrency/
This plugin used & extended custom fields for wp users & recommendend use plugin “User Registration” (Plugin URI: https://wpeverest.com/plugins/user-registration & https://wordpress.org/plugins/user-registration/)

Summary

Referral-system-IVD named
This plugin can be extended and updated by me in the future
Anyway, I plan to expand the range of your plugin for widespread use.
A full description of features is below.