I installed it as it's free, I have the other lightmeter app for my iPhone and is relatively accurate, the new app is close to but not quite the same as the lightmeter app of old. I guess they could be used in a pinch. If one has an idea of what the light is anyway, it's a double check. If one could be made with a zone system dial, color corrected and accurate that would be nice, oh, that's my Pocket Spot!