How do I specify different icon images (each with different size) for different devices? Or do I need to export the app for each device separately?
What you do is use different resource directories with the images for specific devices.
See the "Overriding Resources" section of the programmer's guide in the SDK..
Basically, you have the devices specific things in directories for specific devices, like
resources-fr230
and
resources-vivoactive
in addition to the normal "resources"
You want to have the common stuff in resources, and the device specific stuff in resources-<device>, unless you want to edit a bunch of files when you change something like a string resource.
