CLI apps or so called command line apps are a fantastic way to learn language features and also to do some cool stuffs.
Even though it is totally possible to build any CLI app with your bare hands(which we highly reccomend during initial learning phase) you can use some of the below packages to make your life little more easier
- https://github.com/sindresorhus/slugify-cli - JavaScript
- https://github.com/sindresorhus/delay-cli/blob/master/cli.js - JavaScript
- https://github.com/cdeil/python-cli-examples - Python
Similar approach can be taken for any language
If you know react and if you wish to reuse it to build some crazy cool CLI apps checkout the below link