Chapter 3. Genres, install bands and what "top" means

How the Play Store groups apps, why installs come in bands, and how to rank fairly inside a genre.

Genres

The Play Store has 49 genres: application genres such as Education or Finance and game genres such as Puzzle or Strategy. Each listing has one main genre. Use the genre id (EDUCATION, GAME_PUZZLE) in queries.

Install bands

Google shows installs as bands: 1,000+, 10,000+, 100,000+, and so on. Inside a band, apps look equal on the store, so the API adds an estimate (installs.real) to tell them apart. Filter by the band's lower bound (min_installs), sort by either.

Fair rankings

"Top" depends on the question. Most installed favours old giants; best rated favours small apps with a handful of five-star ratings. A useful middle ground is to require a minimum number of ratings and then sort by score:

/search?category=HEALTH_AND_FITNESS&min_ratings=10000&sort=score

For what Google itself ranks, use the charts: /charts?country=US&category=HEALTH_AND_FITNESS returns the store's top free list for that country.