Unfortunately no, CoFlo currently is C and C-like C++ only. Long-term, I’d like to support more languages, including various assembly languages, and in fact my current work is setting up some infrastructure for that. But any such support is a long way away at this point.

I’m not aware of a tool that does generate CFGs from assembly, but I wouldn’t be surprised if there are some out there. In some ways it’s an easier task, and I have run across a number of academic papers on the topic (googling something like “decompiling assembly code” should turn up some links).