Waves

It's never the camera, always the cameraman :D Good photographers also don't blame it on their camera that their images are in focus :P

Exceeeept that my camera's screen has a few cracks on it that make it hard to focus I think.

Hmmm okay okay :D Well, most phone cameras can handle 'manual focus' if you install an app for that, on iOS it's even called manual I think, or if on Android there will be a solution as well. As long as these cracks are on the screen your camera will keep thinking it's the fist 'point of interest' and keep focussing on that :D