Android App download: go to the www.itrack.top website
IOS App download: just search gpsitrack on appstore
1. Why the GPS tracker device is off-line?
Maybe 3 reasons: i.e. device power off or outage; weak or none signal;SIM card debts or GPRS service overdue.
2. How can you handle with Question 1?
Firstly use your phone call the number of SIM card, then check the voltage and current data whether beyond the specified range or switch off the circuit; Take off the environment of closed or the mental objects; Call the operator of SIM card to assure the card is debts or GPRS overdue and pay the fee or update GPRS.
3. Why you can not monitor?
Because you didn't set up the specific number and open the caller display of you SIM card. The latter will affect the former and lead to monitor failure.