What size atrboard in sketch should I choose for iOS design?

Question

User interface

Starting to design the screens of a mobile application for iOS in sketch, what size artboard to choose if the application is supposed to be for iPhone 4s and higher, that is, with different screens. Or will you have to make your own layout of the same screen for each size 4s,5,6,6plus for the developer?
Thank you.

Answer 1

application for iPhone 4s

320x480
Keep in mind that when screen size is specified, it is the size of the entire screen, including the top notification bar.
There are 3 options: correct, compromise and lazy. Lazy - you draw one layout, which will simply be proportionally scaled for other resolutions. Correct - you draw separate layouts for different resolutions, trying to optimally use the features of each screen (this includes not only the available physical space on the screen, but also the quality of graphics, which should be higher for older models with high pixel density). And compromise - you draw one layout, which will be just rubber, like rubber sites.
The choice of option depends on resources (skills of developers, their salary) and terms.