Some app's integrations never make it into Zapier's public directory. You'll need to search their blog or help docs for an invite link. We've gone out and done that so you don't have to.
Note: We've only included apps that have their invite link on a public-facing website and seem pretty happy for people to use them. If you're on here but don't want to be (or you find a broken link/app), just email us at firstname.lastname@example.org