Secure Https
by Davis
Disallows images to be displayed over http. This keeps the green lock at the top of your broswer 🙂 The extension can either proxy http images through your https or display this error:

Install
composer require davis/flarum-ext-securehttps
Disclaimer
This extension is still in beta abandoned. Please refrain from using in a production environment.
To Do
Proxy non https images through php