STEROID components are accessible from Lightning App Builder, which you can just Drag & Drop to quickly assemble apps.
You can access Lightning App Builder in two ways
1. Lightning Experience : Record Details Page
Access Lead record details page and click Edit Page menu option
Now you can Drag & Drop STEROID components as you see fit.
2. Standalone Mode : Lightning App Builder
You can access STEROID components from Lightning App Builder in a standalone mode
