I think there's a bug in the Prey Android app when installed on a Chromebook through the Google Play Store.
After installing it, I have been occasionally getting the following email indicating that my chromebook hasn't contacted the Prey servers (and so I assume it has no functionality.)
Google ASUS Chromebook Flip C302
This device hasn’t contacted Prey’s servers in 1 day. If this is unusual or you believe something could have happened to it, we recommend you mark it as missing on your online panel. We’ll gather a Report as soon as it goes back online.
Either way, we’ll let you know when it reconnects with Prey
My laptop is listed as a supported device, so I'm not sure what the problem is.