Methodology
Sources
All data comes from public Apple sources: the iTunes Search API for app metadata, and Apple's public ranking feeds for chart positions. Nothing is scraped from the App Store website.
Coverage
Five storefronts: United States, United Kingdom, France, Germany, and Brazil. All 22 published App Store categories. Top free, top paid, and top grossing charts.
Refresh cadence
Rankings refresh once per day per (country, category, ranking type). Metadata refreshes when an app first enters a chart, when its ranking changes, or when a user views its detail page.
