I wanted to create something similar before I knew Jelliesapp existed, so I don't think I'm going to be making it again
Why not make your own? Jellies app is clearly not an established brand/product. To me that means that they’ve only verified that someone else thinks your idea is a good one. Maybe your version will be the one that gets established.
I have to look on why their product didn't get established, they've put in enough effort to make this product a good on.