What Affiliate app is best?

[TerraFirma]

We would like to have an affiliate app that allows us give a unique url to a partner/influencer/affiliate etc and then allows us track what traffic they send and the sales this traffic generates.

I'm aware of Shopify Collabs but the problem is that there is no attribution after the original visit (i.e. it tracks the visit/revenue if the user buys directly after having clicked the link but if the user clicks the link, browses, goes away and then comes back via another channel it does not track this sale as being linked to the original visit).

Is there any app that will track subsequent visits by the same user who was first introduced to the site via the affiliate link?

[tobebuilds]

Maybe you can add a tag or metafield to customers who ordered from a specific influencer's link? That way, you can permanently associate a customer with whoever referred them.