We compared multiple apps with the percentage pricing models that has already been implemented, we charge customers on the basis of revenue they make, But wait it's not as easy as it sounds, this app would also not over charge the customer if they are moving to another pricing tier with just  $1 or even $100 extra revenue. 

The way our pricing work, app would be free of charge but we will charge our users with the amount of extra sales that we make for them on a monthly basis, The above pricing model gives a glimpse of what we charge our users on a monthly basis.