Performance monitoring durring development

Performance monitoring durring development

I have a single page app with a dozen or so internal pages, and a lot of javascript glue holding it together. I would like to write a test that would go through the application basically like a user would. 

The two most important objectives would be to measure how long it takes to run through the test, with page loading and scrolling on different devices, and also find things that have stopped working.

Does anyone have any suggestions as to how I would go about doing this?

-Josh