Included since version 3.8 of the theme

Eventer is an exclusive plugin developed to create and manage event posts for your website. It is a premium plugin available on Codecanyon at price of $39 but is included with the NC theme for free. To be able to use the Eventer plugin with the Native Church theme, it is recommended that you disable the built in events manager from your WP Dashboard => Native Church => Theme Options => Event Options

Note: Once the built in events manager is disabled, you will not be able to use the page builder or normal widgets ‘(N) Featured Event’, ‘(N) Upcoming Events’, ‘Event Grid Minimal Style Widget’, ‘Upcoming Events Listing Widget’, ‘imithemes – Event Grid and Timeline Style Widget’ won’t work. Also these page templates ‘Event Category’, ‘Events Classic’, ‘Events Grid’, ‘Events List’ & ‘Events Timeline’ won’t work anymore. If you are already using any of the mentioned widget or page template then make sure you change or delete them.

To use Events plugin at it’s best, please see the official documentation here