The following list shows the sizes needed for the graphics.


Short list of needed assets used for most devices:


iOS
Android
iPhone (at least 640 x 960 px)
Portrait (at least 1600 x 2560 px)
iPhone 5 (at least 640 x 1136 px)
Landscape (at least 2560 x 1600 px)
iPhone 6 (at least 750 x 1334 px)

iPhone 6 Plus Portrait (at least 1242 x 2208 px)

iPhone 6 Plus Landscape (at least 2208 x 1242 px)
iPad Portrait (at least 1536 x 2048 px)

iPad Landscape (at least 2048 x 1536 px)


Note:  Please make sure that the aspect ratio of the pictures are the same as suggested above. 

Extended list for more display sizes and aspect ratios:


iOS
Android
iPhone 4s (640 x 960)Portrait (320 x 512)
iPhone 5/5c/5s/SE (640 x 1136)Portrait (640 x 1024)
iPhone 6/7/8 (750 x 1334)Portrait (800 x 1280)
iPhone 6/7/8 Plus Portrait (1242 x 2208)Portrait (960 x 1536)
iPhone 6/7/8 Plus Landscape (2208 x 1242)Portrait (1600 x 2560)
iPhone X Portrait (1125 x 2436)Landscape (512 x 320)
iPhone X Landescape (2436 x 1125)Landscape (1024 x 640)
iPad Portrait (768 x 1024)Landscape (1280 x 800)
iPad Landscape (1024 x 768)Landscape (1536 x 960)
iPad Portrait Retina (1536 x 2048)Landscape (2560 x 1600)
iPad Landscape Retina (2048 x 1536)