While designing a website for bootstrap, I noticed there weren't any correct guide-templates for the smaller devices. With mobile-first, I though this was unacceptable, so I generated a few.
In the container folder, you'll find the columns that apply to a container-based grid. In the fluid folder, you'll find the column that rise from a top-level grid in a fluid layout.
You can request additional devices through pull requests. In your pull-request, please prefix your device with the bootstrap screensize prefixes (xs, sm, md, lg). If none of this makes sense to you, you can also open an issue to request additional devices.