See this wiki page to learn how to create an extension.
There are two tiers of extensions:
- The Official extensions: These respect the Best Practice Guidelines, and are fully reviewed to grant you maximum performance and compatibility across the versions of GDevelop and of the extension.
- The Community extensions: These respect only the Best Practice Guidelines, and are not reviewed beyond that. There may be bugs or they could be totally non-functional, keep in mind these risks when using them.
Here are some useful links: