BlockSurvey - Privacy-focused surveys, polls & forms
Apple App Analytics - Apple's very own iTunes Connect App Analytics
Refiner - Customer Feedback Surveys For SaaS
My Motiff - Allowing you to stay connected in realtime
Surveys in Slack by Polly - The world's first fully immersive Slack-based survey product
Usage Analytics in appFigures - Track usage for your app along side downloads, ranks & more