Where are the Flow source files or how does one make a backup?

[Johns-305]

I already lost a Flow when the app crashed.  Lost a lot of time.

What is the best way to backup flows?

I'm using, I guess, a personal account, not my O365, but that shouldn't matter.

[MichaelAnnis]

You can copy each subflow to a text file. That is the best we have come up with so far.