Apkscale`, an open-sourced Gradle plugin, helps measure the app size impact of Android libraries by scanning output directories and measuring sizes of `.aar` files. It provides a simple approach to Android library measurement, allowing developers to create APKs without and with the library, measure the size difference using `apkanalyzer`, and generate reports in various formats. The plugin is designed for Android library developers who want to measure their libraries' size impact directly from their projects, reducing the risk of unexpected size regressions during development.