Instabug - The top apps in the world rely on Instabug for beta testing, user engagement and crash reporting.
Smaller - Make your websites load faster
Userbrain - Easy, fast, and affordable user testing for websites and prototypes.
Website Grader - Grade your website's strengths and weaknesses in seconds.
UserTest.io - User testing made simple. High-quality, affordable user testing solutions from real users, here in the UK. Improve your usability!
Checkbot - Checkbot will boost the SEO, speed and security of your site by checking you're following 50+ web best practices. Browser extension with free and paid plans.