eveal brings the power of tools like Firebug and Web Inspector to iOS developers. See your application's view hierarchy at runtime with advanced 2D and 3D visualisations. Debug view layout and rendering problems in seconds.
Website performance is about two things: how fast the page loads, and how fast the code on it runs. Plenty of services will make your website load faster, from minimizers to CDNs, but making it run faster is up to you.
Jeff Huang, and Charles Zhang. Proceedings of the ACM International Conference on Object Oriented Programming Systems Languages and Applications, volume 47 of OOPSLA '12, page 451--466. ACM, (October 2012)