Very nicely thought out and presented. I like the app and the old shutter speed levels will be a welcome addition. The light measuring phototransistor would be excellent. If one could be placed in a bellows near the front of the camera, perhaps at or near the rear of the lens, it might be possible to see and record the actual exposure for timed shots, that would be an incredible advance. Especially in the the range from one second to a few minutes.

Thanks,
Curt