Last year, Google introduced the Chrome Apps & Extensions Developer Tool which improved upon the developer experience for debugging apps and extensions. The a new version of the tool has been released which allows developers to audit any app or extension and get visibility into the precise actions that it's performing.
Once the Chrome Apps & Extensions Developer Tool has been installed, it will start locally auditing extensions and apps as they are used. For each app or extension, developers can see historical activity over the past few days as well as real-time activity by clicking the “Behavior” link.
The tool highlights activities that involve a developer’s information, such as reading website cookies or modifying web sites, in a privacy section. It also provides the ability to search for URLs to see if an extension has modified any matching pages. If debugging an app or extension, developers can use the “Realtime” tab to watch the stream of API calls as an extension or app runs. This can help track down glitches or identify unnecessary API calls.