How do I enable this feature? I saw it in the "What's New" section, but can't find a way to enable it. I have a Galaxy Note 2.
If you're using a Jelly Bean Android system, you don't need to enable this feature at all. Each push notification you'll receive will be an interactive JB notification.
Note - all reminders/notifications are a Premium-only feature. With a Premium account, you can go to the Settings -> reminders on the web-app at https://todoist.com , choose a default notification method and use reminders to receive such notifications.