According to the instructions of the Saudi government, it is mandatory for all Hajj pilgrims to carry a smart phone.

Hajj pilgrims must learn the mandatory mobile apps before their departure.
The apps mandated by the Saudi government are (Tawkalna) and (Itamrna).
After coming to Saudi Arabia, you will have to buy a local mobile SIM and internet package. Before leaving for Hajj, pilgrims should download Tawaklan and Aitmarna mobile app in their mobile phones and how to use them and Understand well.