Shopify's own admin only shows data for your own store. When you want to see how a competitor's store is built, or which products are selling well elsewhere, a browser extension reads the public storefront and surfaces that information without you needing to inspect the page source yourself.
Inspect a store's theme and installed apps
Koala Inspector detects which Shopify theme a store uses and lists the third-party apps running on its storefront, useful when you want to replicate a competitor's setup or check what tools a well-performing store relies on. The free plan covers occasional lookups; the paid plan raises limits for regular use.
Research bestselling and dropshipped products
PPSpy is aimed at dropshippers, estimating which products a Shopify store sells the most of and tracking store performance over time. Treat these figures as estimates rather than exact sales data, since neither extension has direct access to a store's private order data.
What these extensions cannot see
Both tools read publicly available storefront signals, such as theme files, app scripts and page structure, not a store's private sales figures, margins or supplier costs. Use them for directional research and idea generation, then verify assumptions with your own testing before committing budget.