But comparisons and estimates are becoming more plausible thanks to new travel and transportation app indexes from App Annie, a Beijing-based mobile analytics company.
App Annie’s statistics for downloads are cited by investment analysts more often than any other market research firm’s data, though rival Onavo is favored when it comes to estimates of revenue and in-app purchases.
Helpfully, App Annie’s new monthly travel indexes categorize apps by four subcategories: “travel aggregator”, “hotel and lodging,” “ground transportation”, and “airlines”.