Okay here is the link:HexViewer
The default bit grouping and bytes per line are configurable via the settings file. Currently, to initiate the hex view, you select the command from the command palette.
Just start typing "Hex Viewer" in the command palette to see the commands. One allows you to toggle the hex view on and off. The other two allow you to change the bit grouping and bytes per line on the fly (it will open the quick panel with the available options).
The Hex View tab is a read only tab that replaces the current open file. When you toggle back, the hex view closes and the original file is opened. If you save the hex view as a file, it becomes an actual file that is no longer linked to the source file (the original file will pop back up in this case and you can do it again).
Let me know if you have issues or suggestions...basically, just give me feedback so I know if you like, hate it, etc. I am considering this a beta since I am the only one who has tested it so far.