The goal of all plugins is to enrich a list of items and make it more valuable (i.e. better search and more data understanding).
Before using make sure you have configured it properly (i.e. configuring api keys).
If you are processing your data already you can go to queue to monitor the process of enrichment.

WTJ

This is a plugin which analyzes website and gets info like meta_keywords, meta_description and meta_keywords

Tech detector

This is a plugin which analyzes website and gets info like tech (list of technologies), lang (detected lang on website)

Hunter

This is a plugin which finds a list of emails for a website i.e.: emails_list, hunter_first_name, hunter_last_name

Clearbit

This is a plugin which finds a company information for a website.

Ecommerce crawler

This is a plugin which finds phones, couriers and psp_providers

For more information about plugins from a technical point please go to:
https://github.com/itemsapi/curlist/blob/master/docs/PLUGINS.md