It states it is compatible with Googles Nest Protect. Does this mean it will work in unison with the Google nest app or does it only work with the separate First Alert app?

Hi Bill, thank you for your question. No, the Nest App does not support the SC5. To have both Nest Protect and SC5 units together in one app, the Google Home App must be used. The SC5 is enrolled via the First Alert App and then can be linked to the Google Home App. Your Nest Protect devices are supported in the Google Home and will be there already if you download, install the app and login. Then, the First Alert App or the Google Home App can be used to link to each other. The SC5 devices will appear in the Google Home App. - Maria