I love the concept, but the script seems to be a bit broken?
It seems to be hardcoded to use $HOME/git/magic-tape/ as the directory it runs from, which isn't going to be true for most people. You can use basename -- "$0" to get the directory the script is running from.
UPDATE: The directory structure of the program has been updated. Instead of keeping everything in ~git/magic-tape/, now various files and directories are kept in various places.
This way,
the magic-tape.sh is in ~/.local/bin/
the magic-tape cache files are all in ~/.cache/magic-tape/
the configuration text file will be created in ~/.config/magic-tape/