Apple App Analytics - Apple's very own iTunes Connect App Analytics
SwipeWell - The only tool dedicated to helping you save, organize, and reference marketing examples (so you never feel stumped).
Appfigures for Android - App analytics & insights for mobile publishers
AppGrowthLab (by SplitMetrics) - 55 app growth lessons from 30 app marketing experts
Braavo Analytics - Essential app analytics for busy founders
Growth Tower App Analysis - Top 500 US iOS apps & ASO analysis