Mobile-first design means creating apps and sites that work great on your phone...

https://emilioezho292.theglensecret.com/is-it-better-to-cut-features-on-mobile-or-keep-the-same-experience

Mobile-first design means creating apps and sites that work great on your phone right from the start. It focuses on fast loading, easy-to-tap buttons, and simple menus you can use on the go