Advertised as free but in order to use it, you have to upgrade. It only allows you to do ONE upsell for free. Past that that you cant create an additional unless you pay the associated fee to upgrade. Other than that it is sleek and easy to use.
Whilst we appreciate your feedback, we feel this is an unjustified review of SellUp. SellUp clearly states it is free for 1 Upsell so installing the app to then leave a negative review could be against ToS. Please reconsider this review.
Shopify Partner & Expert