The best way to keep your list feed clear in your Jolt app is to create your reoccurring lists as Checklists rather than Forms in your Jolt Web Account. While forms are used more for one time occurrences that can be created at anytime, checklists are designed to be placed on a Repetition Set. When a checklist is not completed, the next time the list is created on it's Repetition Set, it is designed to replace the old list instance rather than to pile up on your feed.
The incomplete lists will, however, appear on your Jolt web account for you to access and review at any time.
For more information on how to clear old list instances from your iPad and Jolt web account, please reference the article How am I able to clear out old lists on my iPad?