I’ve been recommending RawDigger for some time now as it is the best program for assessing how I’m executing on exposure. It’s also good for assessing raw image quality; see for example Sony 11+7 Bit File Format: Gapping.
RawDigger is the best tool available for anyone looking to hone their exposure technique aka ETTR. Highly recommended, indeed RawDigger is mandatory for the serious shooter.
Below—is this image underexposed in the shadows? Overexposed in the highlights? How would you know (the camera won’t tell you correctly). RawDigger histogram will show you the answer. Below, the images are being viewed in FastRawViewer for another purpose.