Top Charts are the ranked lists of the most-downloaded apps by category and country, a high-traffic browse surface driven mainly by recent install velocity.
Top charts rank apps — split into Free, Paid, and Grossing — within each category and storefront. Position is governed largely by recent download velocity rather than all-time totals, so the charts reflect what's hot now and can shift quickly. Appearing in them is valuable because charts are a major browse surface: millions of users scroll categories without searching, and a high chart slot puts you in front of them.
Charts also create a flywheel. Climbing brings more visibility, which brings more installs, which feeds the velocity that determines chart position — momentum that compounds in your favor or against you. Your assigned category matters here too, since it decides which chart you compete in; a narrower, well-fitting category can be far easier to chart in than a crowded catch-all.
Example
A new productivity app times a launch push so its installs spike in a single week, breaks into its category's top 50 free chart, and the browse traffic that follows keeps it there.