Do you get charged for using downloaded apps abroad?
No, you don't, but you do get charged for 3G/Using Cellular Data abroad.
There are many apps on the iphone that you can get buy going to itunes.com and creating an account. some are free and some cost money. there are apps such as games work apps or software apps. they can only be purcahsed and downloaded on to ipod touch or iphone. but an app is a software that is downloaded to improve the device or to entertain.