To share a subscription between devices ENABLE the on/off slider in the system Settings of your phone and enter a valid email.
How to find the settings are discussed in Q8 in the FAQ.
Emails are sparse, you only get an email when your last know position is more than 30 minutes older than the current position.
The server will ONLY save position updates if you are moving. It will ignore any new locations that are within 0.1 NM from your last known position. Best is to go for 5-10 minute drive to test that your devices are tracking properly. You need to leave the app running in the foreground.
If you are worried about being tracked, please disable this setting.
Once you have received an email from the server from all your devices any purchase you do on any of your devices will be shared between the three most frequently used.
For any questions, please see the contact tab.