危険物乙４（おつよん）全問解説 - 分野別一問一答と過去問 vs Duolingo: Language Lessons
A data-backed head-to-head — estimated revenue, downloads, ratings and pricing side by side, from live App Store signals. Updated continuously.
Revenue / mo
$800–$5k
$12M–$40M
Downloads / mo
3k–11k
6.6M–27M
Rating
★ 4.49 (—)
★ 4.73 (48M)
Pricing
Free + IAP
Free + IAP
Category
Education
Education
Released
5.0y ago
13.2y ago
Verdict: Duolingo: Language Lessons earns more — an estimated $12M–$40M/mo, versus $800–$5k/mo for 危険物乙４（おつよん）全問解説 - 分野別一問一答と過去問.