Backpack is a free flash card program designed to help you learn foreign language vocabulary. Just enter the words you want to learn and their definitions, then click on the 'Test' button and Backpack will prompt you with the foreign words and keep track of which definitions you get right.
There are a few nice touches to this app. For example, you can label words so that you know if they're particular parts of speech or particular genders. There's an online sharing facility, so that you can use other people's lists of words as well as upload your own lists. An export option allows you to save your flash cards as iPod notes, or print them out in various formats.
You can add synonyms to definitions. If you're getting bored, you can be tested using a game of Hangman. Most thoughtful is an option for you to override a result if you knew the word but typed the answer incorrectly.
Unfortunately, Backpack has quite a few problems. The most ironic is the bad English localisation: numerous parts of the interface are in Dutch, as is the help system. Hangman is called 'Play the gallows' and few of the online lists are anything other than Dutch and another language.
Those that are English-based are often on bewildering topics (the main German decks contain definitions for 'plant extract', 'subsistence farmers' and 'North Atlantic Free Trade Area'), and are littered with typos and other inaccuracies, or contain transliterations rather than native script in the case of Greek decks.
The number of different labels is also small, making them superfluous except in a few circumstances. Testing is equally basic, with few variants available for long-term memorisation.
Provided you stick with your own decks and can work out what various Dutch words mean, Backpack can be a useful tool. However, you may find you need something a bit more powerful. Rob Buckley