Canny - Canny helps you collect and organize feature requests to better understand customer needs and prioritize your roadmap.
Website Grader - Grade your website's strengths and weaknesses in seconds.
Delighted - The fastest and easiest way to gather actionable feedback from your customers
PageSpeed Ninja - One-click page speed boost for WordPress
Wootric - Wootric is software that allows apps and websites to take customer satisfaction surveys so that you can properly gauge the popularity and success of your app through the eyes of the people using it. Read more about Wootric.
WebSite Auditor - The techie's SEO spider: find site issues other tools miss