Add filter button to 4K Stogram to filter only unwatched images/videos

Let's say I subscribe specific hashtag or user and I get all its posts (videos and images). After that if the user or hashtag have 30-50 new images or videos everyday, it would be great to have a button to filter only those new 30-50 images/videos that still haven't watched yet. Now when i preview all user/hashtag posts, I have to count how many watched to not watch those which i watched earlier. I know that you show total posts, how many of them are unwatched, so i only suggest to add one button that filters only those unwatched posts. Thank you.