responsively

Install command: 
brew install --cask responsively

Name: Responsively

Modified browser that helps in responsive web development

https://responsively.app/

Cask JSON API: /api/cask/responsively.json

Cask code: responsively.rb on GitHub

Current version: 1.17.1

Requirements: macOS >= 10.15

Versions:

Intel tahoe 1.17.1
sequoia 1.17.1
sonoma 1.17.1
ventura 1.17.1
monterey 1.17.1
big sur 1.17.1
catalina 1.17.1

Analytics:

Installs (30 days)
responsively 134
Installs (90 days)
responsively 341
Installs (365 days)
responsively 1,216