Price: free Download on the App Store
Now, there are a number of different applications out there that teach vocabulary, namely: SAT Word, WORDList, and Vocab Lab, each with their own Lite versions. Though they each have their own approach, the bottom line is that if you are going to invest your time and eventually your money in one of them, then you may as well go for the one with the most words.
With over 5,000 words the premium version of Vocab Lab blows the competition out of the water — WORDList coming in second with 1000 and SAT Word a distant third with a mere 500. That said, the Vocab Lab Lite has only a small sampling of words — 30 to be exact.
The first section in Vocab Lab and Vocab Lab Lite is simply called "Learn Vocab Cards." In this section you have a "deck" of cards, one word per card. As you move through your deck of cards the program will also keep track of your progress so that you can leave and come back without having to start from the beginning.
Although it is not exactly relevant in the Lite version with only 30 words, in the "Learn Vocab Cards" section you can manage the size of your deck by clicking "+50" or "-50" — a very helpful feature when dealing with the 5,000 words found in the larger version. You can also choose to remove words you have already mastered. Once removed, the words are stored in "Settings & Credits" in case you want to add them back to your deck later.
The Quiz section of Vocab Lab Lite is pretty straight forward, it gives you the definition and you choose the answer from four options. Again, your progress is monitored here as well so you can come and go as you please without loosing your place in the deck.
At the moment the newest version is the 1.5 but they have already posted a list of things to come in the 2.0 version, including graphed quiz results, an option to only be quizzed on the words in your deck, and, for those of us audio-based learners, verbal pronunciation of words. Though the release date is not yet set, past updates have been fairly frequent for this application so you can expect it to come much sooner than later.