Obama used a Blackberry for years before eventually switching to a hardened Galaxy S4 that was so locked down that "it doesn’t take pictures, you can’t text, the phone doesn’t work, you can’t play your music on it" [1]

Trump, on the other hand, does use an iPhone but doesn't have it checked by security experts as often as his aides would like [2]

[1] https://www.digitaltrends.com/mobile/obama-ditches-blackberr...

[2] https://www.politico.com/story/2018/05/21/trump-phone-securi...