Both Android and iOS have very specific guidelines on what an icon for your application should look like, as well as at what dimensions you should provide your icon. Appcelerator has some general information about creating application icons in their wiki, but the steps below go into a little more detail.
- Apple's icon guidelines: http://developer.apple.com/library/prerelease/ios/#documentation/UserExperience/Conceptual/MobileHIG/IconsImages/IconsImages.html#//apple_ref/doc/uid/TP40006556-CH14-SW1
- Android's icon Guidelines: http://developer.android.com/guide/practices/ui_guidelines/icon_design.html
Since each OS has its own unique style of icon, a good approach is to create one icon for each, and save it at all the different required dimensions.
For iPhone and iPad: - Create an iOS icon at 512 x 512 (This size is used during the app submission process)
- Save for iPhone at 2 sizes in the Resources/iphone folder, one for standard res (57 x 57) and one for Retina Display (114 x 114), such as ApplicationIcon.png & ApplicationIcon@2x.png. Titanium recognizes that adding @2x just before the file extension indicates that this asset is for retina display.
- Save for iPad at 72 x 72 pixels, naming it ApplicationIcon_72.png
- Create an Android icon using the guidelines in Android's UI Guidelines.
- Save three resolutions of the icon in android/images/<high | medium | low>/ApplicationIcon.png. 72 x 72, 57 x 57, and 48 x 48. Note: The high, medium and low folders might not yet exist, so you need to create them.
- In Titanium Developer, select the project on the left, select "Edit" in the top of the window, and set the "Application Icon" field to "ApplicationIcon.png".
- When creating your iPad app, you might need to manually select the icon.
- Test in the emulator to see if the icon shows up (you may need to delete the contents of the build/android folder, but not the folder itself. You may need to delete build/iphone, which is safe.)
