FullStory is captures your site visitors' browsing behavior, useful for anyone that wants to better understand their users and how they use your product.
Layer FullStory's digital experience data over your Segment, Tealium, or instrumented events with FullStory Custom Events to create an unfathomably powerful product insight engine.
BundlePhobia is a web service to find out the how much size will a npm package cost your project. It can measure the size of CSS/Sass libs too and report whether the module supports tree shaking.
The same service is available via cli tool and an atom plugin.