Build Time Analyzer from Robert Gummesson is an Xcode plugin that provides an overview of how long it takes to Xcode to build individiual Swift files.
Build Time Analyzer was created so you can easily find any bottlenecks causing large build time increases.
Here’s an image from the readme showing Build Time Analyzer in action:
You can find BuildTimeAnalyzer on Github here.
A nice tool for easily analyzing build times.
See more Xcode Plugins.