No, your Fongo Mobile app requires an internet connection to make/receive calls or send/receive texts.
Since the Fongo Mobile app uses Voice Over Internet Protocol (VoIP) technology, it needs an internet connection, which can be either Wi-Fi or 3G/LTE/5G data connection.
If you do not have an active internet connection, received messages will be queued on our servers for up to 7 days, and then delivered to your device once you have re-established a connection to Fongo services.