Too inconsistent to be worth much.
We cannot generate consistent readings with this App. One of our consulting engineers placed a professional meter next to the App and got widely different readings. We didn't expect the App to be super accurate but hoped that it would give our designers "ball park" readings. The reality is it appears to be no where near close. The same App on different iPhones generates different readings in the same location. Does this camera generate readings from the front or back camera? Do you place it on the lit surface or focus the camera on the surface? The documentation is lacking so it hard to know.