Libby, the library app — Revenue & Downloads Estimate

Appdex shows the range, not a fake-precise number. Every estimate carries its confidence band — and we tell you exactly how sure we are.

Behind this number is an engine that never stops: it re-processes millions of rows of App Store signals every day across 1M+ apps, rebuilds every estimate nightly, and grades its own accuracy against tens of thousands of independently known figures before anything ships. How the engine is tested →