Naturally, if you shoot handheld with an iPhone, it’s hard for it not to be shaky. Both apps offer the same three levels of stabilization, which are set by the sensor and operating system. Standard mode uses only optical sensor stabilization. Cinematic mode is sensor stabilization enhanced by the operating system. Cinematic Extreme (labeled Cinematic+ in Filmic Pro and Extreme in Blackmagic Camera) applies even more intense software smoothing. These last two settings increasingly add latency to the preview image on your screen. I recommend using Standard and then supplementing that in the NLE with a stabilization plug-in for better control.