Office of Digital Humanities
The Android Universe. Android is an open source operating system that had been adopted by many different device manufacturers. Consequently, there is great variation in screen sizes and resolutions.
Here is just one comparison put together by a developer at jacksonkr.com.
For an even more vivid picture of the diversity of Android devices sizes and resolutions see this post at crossbrowsertesting.com.
As you can see, developing for Android can be a challenge due to the great variety of screen sizes you have to support. But the sheer number of users make it an attractive market for developers.
The iOS Universe. The range of devices iOS devices is considerably smaller than in the Android universe, so the different screen sizes and resolutions that you might need to develop for is also considerably smaller. Here are the choices:
iPhone/iPod Touch
| Model | Screen Size (Diagonal) | Resolution |
|---|---|---|
| Original iPhone – iPhone 3GS iPod Touch 1st gen – 3rd gen | 3.5 in. | 320x480 (163 ppi) |
| iPhone 4, 4S | 3.5 in. | 640x960 (326 ppi) |
| iPhone 5, SE | 4 in. | 640x1136 (326 ppi) |
| iPhone 6, 7, 8 | 4.7 in. | 750x1334 (326 ppi) |
| iPhone 6, 7, 8 Plus | 5.5 in. | 1080x1920 (401 ppi) |
| iPhone X | 5.65 in. | 2436x1125 (458 ppi) |
Selected iPad models (see complete list here)
| Model | Screen Size (Diagonal) | Resolution |
|---|---|---|
| Original iPad, iPad 2 | 9.7 in. | 768x1024 (132 ppi) |
| iPad 3rd – 4th gen iPad Air 2 | 9.7 in. | 1536x2048 (264 ppi) |
| iPad Mini | 7.9 in. | 768x1024 (132 ppi) |
| iPad Mini 2nd gen, iPad 4th gen | 7.9 in. | 1536x2056 (324 ppi) |
| iPad Pro | 12.9 in. | 2048x2734 (264 ppi) |
More information on iOS devices:
Wikipedia's Detailed list of iOS devices.
A handy reference for iPhone screen sizes and resolutions.
A handy iOS design reference at ivomynttinen.com.
When you build an app for distribution you should include the icon files that will be used for launching the app. Depending on which devices you are supporting, you may need to supply several different sizes. The specifications for iOS apps are more exacting than for Android apps:
iOS Springboard (Home screen) Icons:
Android Home Screen Icons: According to developer.android.com icon guidelines, "launcher icons should be 32-bit PNGs with an alpha channel for transparency." This citation goes on to list recommended sizes for various display resolutions, but LiveCode only requires a single 72x72 icon for the launcher screen.
Apple requires launch images for all iOS apps. These are static images that appear briefly while the app is launching. They should be the same size as the screen resolution of the device. In other words:
Here is a detailed explanation of app icons required for iOS apps.
Here is an explanation of iOS launch screens (AKA "splash" screens).
Launch images or splash screens are not required for Android apps, but LiveCode allows you to include a 600x600 image, which will be displayed at launch. Some Android experts actively discourage developers from using splash screens in Android apps.