Kudolo Kid GPS Watch, Tracking Watch for Children with SOS Button, Kid Talking Watch for Android & iOS Cellphone (Yellow Color)

First of all, I am an Chinese and I do speak perfect Chinese. I believe these kind of watch are pretty popular in china among my friends so I always wanted to get one for my kid. I tried to buy one from China directly but it didn't work since it doesn't support the frequency (850Mhz) for at least where I live. Then I tried amazon and most of those watches are shipped from China and this watch is the one of the few that I can find on amazon that is actually sold by amazon prime in US. (BTW, those watches are typically priced at ~$30 when sold in China while the so called "international version" like this are always > $60)1. It actually worked on AT&T SIM card, for phonecalls, and it only has 2G as claimed and maybe because of this, the GPS is way off (by at least 1~2 miles)2. this definitely belongs to one of the cheap Chinese product. the watch is cheaply made, the app is a piece of crap and of course the manual are poorly written and even translated poorly into English. For one thing, they didn't even tell you how to turn this watch off! or how to use the app. It took me quite a while to figure out myself. and don't expect much customer service, all they give you is a website, and you can send them an email.So the verdict is that this watch is a piece of junk that doesn't worth more than $20. But I decided to keep this as an emergency tool for my son since he can at least make calls and I can roughly have a sense of location. This is solely because I couldn't find any better choices.