It's fun to look back at how things evolve. In 2012, my team was working on creating a UI responsiveness tool for IE and Visual Studio (for Windows Store apps written using JavaScript). This was at a time when many of the default Windows applications were written using JS and we didn't have good tools for the Window's team to analyze performance problems. It took us a few sprints to get the data collection, analysis, and UI to be useful.
The following sprint saw much better integration between the CPU graph and timeline, enabling range selection, zooming in/out, life cycle events, user generated events, etc. At this point, the tool actually became useful for the app writers :) 4/