You can communicate with your Ontech GSM 9040 in two different ways.

1.With our web interface Ontech Control. Then use the included SIM card and you will not use any app.. The attached SIM card has no public phone number.
You log in via your web browser on computer / tablet / mobile phone and communicate that way. On the tablet and the phone, you can add a shortcut to the home screen so it becomes like an app. See guide here.

2.Via SMS. Then you buy a prepaid card or subscription and can then use our iPhone and Android apps to communicate. See guide here.