Checkout Links by Edi&P

This is awesome for building quick share-able links and even includes QR codes! It like it better than using shopify's built in shareable checkout links because it has a handy little landing page. And you can include your branding on those little landing pages. Plus the dev is super active and building new features all the time! Like they added review integration pretty quickly after I requested it. Only downside is I wish the price was more affordable.