I think more accurately, it's a standalone app that runs on the chrome runtime. You get windows, osx, linux & chrome os all at once. The chromebook is touted as

I think more accurately, it's a standalone app that runs on the chrome runtime. You get windows, osx, linux & chrome os all at once. The chromebook is touted as the secure desktop for the non-technical user. You can take the app and make your own standalone runtime version if you want and audit / test your standalone version to make sure it's only communicating with open whisper systems.