Instabug - The top apps in the world rely on Instabug for beta testing, user engagement and crash reporting.
Siberian CMS - Siberian is an Open-Source and Free App Maker. Unlimited Push Notifications. Unlimited features. Fully Customizable. Download it and build your own app now!
Buglife - Seriously awesome bug reporting for iOS apps
GoodBarber - GoodBarber is a mobile app creation platform.
Sonar by Facebook - Extensible mobile app debugging for iOS and Android
Bizness Apps - Create your own app or become a reseller and build apps for others