Rage Grade by FullStory - Benchmark your customer frustration
LibHunt - LibHunt tracks mentions of software libraries on relevant social networks. Based on that data, you can find the most popular projects and their alternatives.
App Launch Checklist - Planning tool for launching your app successfully
AlternativeTo - AlternativeTo lets you find apps and software for Windows, Mac, Linux, iPhone, iPad, Android, Android Tablets, Web Apps, Online, Windows Tablets and more by recommending alternatives to apps you already know.
ASO Tools by AppFollow - Tools for App Store Optimization in App Store & Google Play
GitSpo - Measure & engage your open-source community