Hexedit

The Hexedit app is a

Hex Editor for binary files.

Use open to open a local file or use OpenSAF to open a file from your google drive.

The default output is in HEX, however you can change it with the menu as show below.  The user has chosen Ascii for output.

The two bottom windows, 0-F are the two nibbles of the byte.  A nibble is a half byte. No, I am not making this up.  That is what it is called.

The two nibbles are always in Hex, 0-F