Can a post-sell or pre-sell app promote products at checkout?

Shopify Apps
1

this there any post-sell or pre-sell app, which can let merchant decide products to promote on checkout flow?
if there is a ab testing feature would be better

2

Not sure what you mean by checkout flow, but to customize the Checkout page your store has to be on Plus plan.

We use Rebuy app, so we can add products for cross-selling on product pages, collection pages, in cart, checkout and on Thank You page. Happy with it.

3

hi, @kgbfashionista

thanks for the reply.

Customize the Checkout page your store has to be on Plus plan
So, checkout.liquid is still works for not Plus plan merchants?
kind of confused about this.
https://changelog.shopify.com/posts/the-checkout-liquid-theme-file-is-being-deprecated

Rebuy app looks fantastic, thanks!