Yes, starting in the Doneit 2.5 update you can now sync your reminders in the system’s Reminders app with Doneit and your tasks in Doneit with the system’s Reminders app. You just need to enable this option in the settings of the app by selecting the ‘Database’ option under the ‘Integrations’ section.

Unfortunately, previous versions of the app prior to the Doneit 2.5 update don’t support this functionality.