Unpack multiple archives recursively in Linux

So you downloaded all the X-Files seasons and every episode is packed in RAR. You can use unrarr to recursively unpack the contents of each archive by following these install steps:

gunzip unrarr.gz 
sudo cp unrarr /usr/bin/ 
sudo chmod +x /usr/bin/unrarr

…then use the utility like this:

unrarr /path/to/folder

It can be a real time-saver.
For ZIP files you can use unzip and a small shell script that goes like this:

for dir in */
do
   ( cd “$dir” && unzip *.zip )
done