Private apps provide Shopify business owners with extended, personalized store features. These apps are built by third-party developers exclusively for your store. They differ from public apps (which are available to many different stores) or custom apps (which don’t require open API access.) It can also allow for additional data integrations with content management systems other than Shopify, by means of an API. Further, private apps allow store owners to extend their selling capacity to custom storefronts, such as mobile applications, video games, and websites.