Foward Cycle allows you to forward your form to a selected user, and then repeat that process until the form is marked as "complete".
This is useful for forms that need to be passed back and forth an undetermined amount of times, such as a "review and approval" process.
To add forward cycle to your form, go into the delivery window and add the forward cycle action to your stage.
As with the regular forward action, you are able to Alerts. For more information on alerts see this article: https://mergemobile.zendesk.com/hc/en-us/articles/360000195912-Alerts-Conditional-Alerts-Conditional-Action
You have three options for forwarding your form.
1) Forward based on a list of users
2) Forward based on a user group
3) Forward based on a field within your form
Regardless of which you choose, remember that with forward cycle the action will repeat until the form is marked as "complete" upon submission.