iOS: Preparing background images for applications

Question

Mostly every iOS application has a view with an image as background. Is there any image sizing guide out there? For example here is an iOS screen designed in Sketch:

Answer 1

There is design nuance in full size background images. Mostly if the scale aspect fill good enough for different sizes you need to design only for the biggest device size after that the rest of them scale to fit. Sometimes some part of background needs to remain visible or if want to keep a low memory footprint for small device sets you need to create smaller alternatives.

Whenever you make a decision with the design size of asset you need to create @3x,@2x variants.

One more thing I need to point out about vector designs. If your design is made only with vectors you can choose pdf vector export. Storyboards can accept vector assets and they are doing very good when scaling in full backgrounds.