Apple App Analytics - Apple's very own iTunes Connect App Analytics
AppGrowthLab (by SplitMetrics) - 55 app growth lessons from 30 app marketing experts
Appfigures for Android - App analytics & insights for mobile publishers
The Creative Marketer - Techniques & tools for copywriters, marketers, and creatives
Braavo Analytics - Essential app analytics for busy founders
Adapty - Low-code price personalization for in-app subscriptions