Foremost is also extremely useful for the same purpose, and I've found it more useful at least in my work during CTFs

https://en.wikipedia.org/wiki/Foremost_%28software%29

A `sudo apt-get install foremost` works on Ubuntu to install it, IIRC

Binwalk is great, I love extracting stuff from big binary blobs of router firmware, or dumping all the memory on a Linux computer with LiME (https://github.com/504ensicsLabs/LiME) and using Binwalk to see what's in there!