GitHub is a great source of third-party addons. A lot of Odoo partners use GitHub to share the addons they maintain internally, and the Odoo Community Association (OCA) collectively maintains several hundreds of addons on GitHub. Before starting to write your own addon, be sure to check that nothing already exists that you could use as is or as a starting point.
This recipe will show you how to clone the partner-contact project of the OCA from GitHub and make the addon modules it contains available in your instance.
Suppose you want to change the way addresses are handled in your instance; your customer needs a third field in addition to Odoo's two (
street2) to store addresses. You could ...