The Pammac English Swahili dictionary is the best ever two-language dictionary on the iPhone/iPod Touch.
It contains more than 1500 translated words and expressions and they are available right on your hands. You dont need to be connected to the internet: no 3G or WIFI needed at all. Just search, find and learn! It will work even in the North Pole.
This App is licensed under the GPL v2 license.