I downloaded the stable one, and it doesn't appear to have any external dependencies (using objdump). Another program I use an AppImage for shows such dependencies:
[...]
NEEDED libdl.so.2
NEEDED libpthread.so.0
NEEDED libz.so.1
NEEDED libc.so.6
[...]
So perhaps this particular AppImage is completely self-contained?
No, I haven't run it 😀