You can't adjust anything from the phone, not even the sound, the battery is not for crying 24 to 30 hours at best, and with the magnetic charging cable it has, you have to leave it very carefully down so that the charger doesn't come out, and this has to be done every day. In short, money wasted.

The main reason I bought it is because it claimed to be waterproof, which is not true, and after about 2 weeks we can't communicate, the child can't hear me and I can't hear him either (very deep sound and interruptions). Also, the range is about 500 meters away from the child's location. So, in a few words, even if they gave it to me for free, I wouldn't use it on the child.

It is excellent as a watch and as a means of telephone communication.
It requires a sim card and without the application, nothing works (not even the time can be set).

The instructions recommend a specific application: Se Tracker2.

Phone calls work perfectly. The ringtone and conversation volume are okay.
The phonebook for 10 numbers and the 3 SOS numbers are okay.

There is an issue with messages, as the application is specific, WeChat, and the reviews are not good.

The location tracking on the maps has a large deviation (definitely more than 500m).

I imagined a watch where one could download apps of their choice, like Viber for example, but it seems that is not possible.