Use it to find technical debt. Often in projects maintained about several years files and classes tend to grow. To find those files in Objective-C that have more than a 1000 lines use
fileize . --limit 1000 --objc
If only Swift files need to be considered use
fileize . --limit 1000 --swift
For Swift and Objective-C files drop the filetype option and just write
fileize . --limit 1000
In general the format is as follows
filesize <path> --limit <number> --<Options>
Options:
--swift: consider only swift files
--objc: consider only objc files
--help: this help
To build from source code use
swift build -Xswiftc "-target" -Xswiftc "x86_64-apple-macosx10.12" -Xswiftc -static-stdlib -c release