Sirius Glass
Subscriber
I have the light meter app on my phone. It agrees closely with the meter in my SLR for an average scene. My phone doesn't support the "incident" mode of the light meter app, so when I want an "incident" reading, I fake it out by using the reflective mode, putting the palm of my hand in the same light as my subject, and aim my phone at my palm. Take a reading, then open up 1 stop. This method has never failed me, and it works for B&W negative, color negative, B&W reversal, and color reversal films. The best part is, the paid version of the app cost me the princely sum of 2.99 USD, and it works great on my Samsung J3 (2016) phone.
Years ago I pointed the Minolta SRT at my palm to get a light reading on the ski slopes. If I used the light meter for a general scene I would get the shape of the snow, moguls, and everything else would be almost black.