I don't think I'll manage to get it into a good enough state by EOD today (only really worked on it today unfortunately)

But here's a screenshot of my visualization tool.

It's a cli application, you give it a list of files or a folder and it will parse all the C/C++ structures in the files provided, calculate their member's alignments and sizes, and spits out an interactive single html file for visualization. Here's it is just parsing the data structures in its own source code.

I'd like to support bitfields, attribute noalign, __randomize_layout, C++, other languages, and have better/more useful tools for doing things like sorting them by size, showing you where you can trivially make your structures smaller, etc.