Most upsell apps change the add to cart or checkout buttons causing our price add-ons, file upload, and other data not to save correctly.
One app that seems to work with all our apps features is Candy Rack.
Candy Rack — All‑in‑One Upsell
One click upsell & cross sell app, Product page pop-up upsell
5 stars (167reviews)
14-day free trial
Please email us and let us know if this app works for you.