UserTesting.com - Usability testing has never been easier. Get videos of real people speaking their thoughts as they use websites, mobile apps, prototypes and more!
Buglife - Seriously awesome bug reporting for iOS apps
Instabug - The top apps in the world rely on Instabug for beta testing, user engagement and crash reporting.
Highlight - "Highlight" physical books through conductive pages 📖✨
Userbrain - Easy, fast, and affordable user testing for websites and prototypes.
Sonar by Facebook - Extensible mobile app debugging for iOS and Android