The image format and size used in the app background are constantly updated with apple

Image format and size used in APP background

1, icon

A large version of your app icon that will be used on the app store. it must be at least 72 dpi, In the RGB color space, and 1024x1024 pixels (it cannot be scaled up ). the file type must be. JPEG ,. JPG ,. TIF ,. tiff, or. PNG. it must be flat artwork
Rounded corners.

2, 3.5-inch Retina Display screenshots

Screenshots for 3.5-inch iPhone and iPod Touch Retina display must be 960x640,960x600,640x960 or 640x920 pixels, at least 72 dpi, In the RGB color space, and in the jpg or PNG format.

3, 4-inch Retina Display screenshots

Screenshots for 4-inch iPhone 5 and iPod Touch (5th generation) Retina display must be 1136x640,113 6x600,640x1136 or 640x1096 pixels, at least 72 dpi, in the RGB color space, and in the jpg or PNG format.

4. iPad screenshots

IPad screenshots must be. JPEG ,. JPG ,. TIF ,. tiff, or. PNG file that is 1024x768,102 4x748,768x1024,768x1004,204 8x1536,204 8x1496,153 6x2048 or 1536x2008 pixels, at least 72 dpi, and in the RGB color space.

Image size and size used in the program

1, icon

50*57,114*114*72,144, 72*144,512*512 *

2, default

320*480,640,960,640*1136,204 8*1536,102 4*768,153 6*2048,768*1024