Design app ui on smaller screens?

Should i design my app ui on a smaller screen like iphone 5 so that it will fit well on most screens? i remember someone commenting this on github that they practice designing on smaller screens so that the app fits well on all screens. Is this a helpful practice?

I think it depends on the project. If it is a desktop app, I wouldn’t care much about it.

It is called mobile first design and many frameworks like Bootstrap are designed with this mobile first approach. Actually, since the end of June, Google will start using its mobile first crawler, so I guess it will be a must in the future of website development.

It’s [much] less painful to make it work well for mobile then go up than it is to start wide and try to go down (in most cases). With the caveat, as @SpaniardDev says, if it’s a desktop app then obvs design for that.

As a rule, most traffic comes via mobile these days, so it’s pretty critical to make it work, and doing it that way removes a lot of pain

i am working on a react native mobile app so thats why i considered this approach