It is mentioned in the Quran that Allah has created everything to be halal for us to use. We are not only using cell phones but also cars, electricity, TV, radio, planes etc.

Allah says: “Say (O Muhammad (peace be upon him)) “Who has forbidden the adoration with clothes given by Allâh, which He has produced for His slaves, and At-Taiyyibât (all kinds of Halâl (lawful) things) of food?” Say: “They are, in the life of this world, for those who believe, (and) exclusively for them (believers) on the Day of Resurrection (the disbelievers will not share them).” Thus We explain the Ayât (Islâmic laws) in detail for people who have knowledge.” 7:32

What is not permissible for us to do is to worship Allah in a way that is innovated and that the Salaf didn’t do and is not in the Quran or Sunnah.