There is a third party package available to server-based instances but nothing generally available for cloud-based users that I can find. Minimum requirements would be:
1. Ability to assign single to many approvers for a given document
2. Approval requests relayed via email to approvers
3. Ability to configure approval request to run serially (1st approver must approve before 2nd) or in parallel (Approvers can review and approve in any order)
4. Ability to assign a Due Date to approval request
5. Automatic email notification / follow up on approval tasks not completed
6. Email message included with approval request that is configurable
7. Approval/Rejection can include a comment / note from Assignee
8. Configurable option to end the approval process if it is rejected by any participant
9. Configurable option to end the approval process if the document is changed before the process completes
10. Automatic notification to Creator when approvals have completed or been rejected
11. Document approval history available for x days/years