Is there a free upsell app for Shopify I can use?

I am also looking for an upsell app. I am thinking of using Cross Sell, but it's $9.99 per month.

I would be cautious when using free upsell apps for Shopify. Often times, when apps are free or low-cost, there are many glitches and bugs. These apps are often not worth the headache!

I recommend that you use a reputable app that gets the job done properly, even if you have to pay for it.

What are your products? What are you trying to upsell? Are you trying to upsell the products? Are you doing this pre-checkout? Is the upsell a part of the post-purchase process?