The gold standard for modern Android cross-referencing is the official platform hosted by Google: Android Code Search . Powered by the Kythe indexing backend, this platform provides an IDE-like interface natively within your web browser.
Using these tools is refreshingly simple and doesn't require a user account or any configuration. Here's a basic workflow: xref aosp free
Searching for the Android Open Source Project (AOSP) source code can be a daunting task given its massive scale. Fortunately, several free "xref" (cross-reference) tools make navigating this ecosystem much easier. These tools allow you to jump between function definitions, find usages of specific variables, and browse different branches of the Android OS without needing to sync hundreds of gigabytes of data locally. The gold standard for modern Android cross-referencing is