Extend the functionality of your store
Ecommerce plugins found in the Shopify App Store add features to your store.
Shopify App Store
The Shopify App Store is a collection of free and premium plugins that extend the functionality of your online store. It is a great way to adding more specialized features to Shopify. Here are two examples:
PixelPrinter
Pixel Printer creates and prints custom shipping labels, invoices and receipts.
Mapify
Mapify allows you to view all your customers instantly on a beautiful world map.
Add your own features
With the Shopify API you can add new functionality to Shopify yourself. You can use your favorite programming language to create new apps for your online store, and you can even share them with other Shopify merchants on the App Store. All you need to get started is a Shopify Partner account.
API Documentation
To get started we recommend you take a look at the intro video, the documentation or the development forums.