The listing is typed into each console, not into app.json, and the stores' image rules are strict:
| Asset | Google Play 1 | App Store 10 |
|---|---|---|
| Icon | 512 x 512 PNG, alpha allowed, up to 1 MB | Taken from the build's 1024 x 1024 icon |
| Banner | Feature graphic, 1024 x 500, no alpha | None |
| Phone screenshots | 2 to 8; 320 to 3,840 px; long side at most twice the short | 1 to 10 at 6.9 inch (e.g. 1320 x 2868), no alpha |
| Text | Name 30 characters, short description 80, full 4,000 | Name 30, subtitle 30, keywords 100 |
Play promotes apps with at least four screenshots of 1080 x 1920 or larger in 9:16. The emulator in this book captures 1080 x 2400, which is 9:20: more than twice as tall as it is wide, so Play refuses it as it is. Crop the status and navigation bars away to reach 9:16, and drop the alpha channel:
magick catalog.png -crop 1080x1920+0+134 +repage -alpha off play-1-catalog.png
identify catalog.png play-1-catalog.pngOutput
catalog.png PNG 1080x2400 1080x2400+0+0 8-bit sRGB 240718B 0.000u 0:00.000 play-1-catalog.png PNG 1080x1920 1080x1920+0+0 8-bit sRGB 188309B 0.000u 0:00.000
The crop also loses the tab bar, so pick screens whose content fills the frame. The App Store's 6.9-inch iPhone screenshots need an iOS simulator or device, so they come from a Mac or a cloud device service.