Store categories to read the charts of (App Store: top free + top grossing per genre; Google Play: the category page and its "see more" clusters). Ids: business, developer-tools, education, entertainment, finance, food-drink, graphics-design, health-fitness, lifestyle, medical, music, navigation, news, photo-video, productivity, reference, shopping, social, sports, travel, utilities, weather, dating, parenting, personalization, communication, auto-vehicles, house-home, events, beauty, games, games-action, games-adventure, games-arcade, games-board, games-card, games-casino, games-casual, games-educational, games-music, games-puzzle, games-racing, games-role-playing, games-simulation, games-sports, games-strategy, games-trivia, games-word. Apple genre ids (6013) and Play ids (HEALTH_AND_FITNESS) work too.