Apple released its much-awaited iOS 4 update Monday for the iPhone 3G and 3GS, as well as the second and third generations of the iPod Touch. However, not all iOS 4 features have rolled out for all devices, and first-generation versions of both the iPhone and the iPod Touch won't get the update at all. Here is a chart breaking down what you do or don't get with iOS 4, depending on which device you have.
| iPhone 3G | iPhone 3GS | iPod Touch second generation | iPod Touch third generation | |
| Multitasking | No | Yes | No | Yes |
| Home screen folders | Yes | Yes | Yes | Yes |
| E-mail upgrades | Yes | Yes | Yes | Yes |
| Background wallpaper | No | Yes | No | Yes |
| Camera zoom | Yes | Yes | N/A | N/A |
| Photo gallery with Faces/Places support | Yes | Yes | Yes | Yes |
| Spell check | Yes | Yes | Yes | Yes |
| Searchable text messages | Yes | Yes | N/A | N/A |
| Bluetooth keyboards | No | Yes | No | Yes |
| Support for iBooks | Yes | Yes | Yes | Yes |