The Lytro Light Field camera was probably the most exciting photography product that came out last year. Although it offers low-fi images, it takes photographs in a completely different manner to regular cameras, allowing you to choose and re-choose what element of your photo you want in focus after the fact. Since then, we've heard word that other companies are working on bringing sensors that can also shoot a single image with multiple depths of field. However, Developer Arqball believes it's managed to replicate the Lytro using just your iPhone's sensor and an app: Focus Twist. So how does it do?