In the Slack group I've both helped people write their own or done contract work to build what's needed.
There is a subset of people however, that would like to learn how to build addons themselves, but don't know how to start.
As I know how to build addons, and really enjoy coaching/teaching, I decided to create a series of courses to walk people through building the various different types of addons. My first, Addon Development 101 is in a couple of weeks.
You can register here: https://silentzconsulting.com/courses/addon-development-101.
I'm very excited to help people learn.