I do not see any reference to a smartphone in the Torah. The Rambam does not refer to smartphones. As with virtually everything not specifically referenced in the Torah, there are chekei deios between the Poskim. I personally know several Rebbes and Rabbonim who have -unfiltered- smartphones, forget filtered ones. There is no clearly no issur d’oraisa involved here. Anyone who suggests otherwise is deluding himself and others.
