You can add three different types of apps to your Shopify store: public, custom, and private. You can use Shopify apps to enhance your Shopify admin or add new features.
There are two types of public apps, listed and unlisted. You can install listed apps from the Shopify App Store. Unlisted apps don't appear in Shopify App Store search results or categories. Instead, you can install them from the app's App Store listing or the developer's website.
Both listed and unlisted apps must pass the Shopify App review process.
Custom apps can be installed only on a single Shopify store, and are not listed on the Shopify App Store. You can install a custom app on your store by using an installation link provided by the app's developer.
Draft apps are used by Shopify Partners during development, and can only be installed on development stores for testing purposes. Installing a draft app on a development store disables store transfer permanently.
Draft apps can only be installed on your store after Shopify review, or once they're converted to a custom app.