The description is based on Xiaomi Pocophone F1 phone. Depending on the model name and the Android OS version, the setting name and the screen may vary.
1. Battery Optimization Setting.
You have to exclude the 'GeoFamily' app from the list of the 'Battery saver' apps, if your Android OS version is Marshmallow (ver 6.x) or later.
2. Autostart Setting.
You must allow the 'Autostart' setting of the GeoFamily app.
3. Notifications Settings.
Phone Settings > Notifications & status bar
Phone Settings > Installed apps > Select the GeoFamily app on the apps list.
4. System Settings.
Activate 'Mobile data', 'Wi-Fi', 'Sync' and 'GPS'.
Leave 'Battery saver' disabled.
5. Always keep the Google Play Store up to date with the latest version of app.
Find the 'GeoFamily' app in the Google Play store and activate the 'Enable auto update' setting.
★ Click here for the information on how to set up your counterpart Controller user's smartphone.