Assign the class UIStoryboardSegueFromRight to the custom segue in the storyboard.
To create an Unwind Segue, you'll need the code below in the first controller. You'll use the segueToMe to connect to the Exit in the second controller. Give that Unwind segue the identifier e.g. "returnToMainViewController".
This keeps crashing for me on the UIStoryboardSegueFromRight function.
Sometimes it works and sometimes it crashes with an unspecific error.