Variable FPS with mobile phones (Galaxy S7 or iPhone 8)

Hi I got my tentacle Standard Set and need to test it before using it a a shoot. I connected o sync-e to my mobile phones (S7 and Iphone8) with the correct cable. Found out that the audio tc was 30 FPS as expected, but the phones recorded at 30,52 (or something). Did some research and found out that they record with variable frame rates. Was kinda surprised because iPhone is supported with a cable on the original accessories page. But if the iPhone records at a variable frame rate, doesn’t this mean that it will go out of sync with the steady audio tc?? Please help me out to get this sorted. Thx