First we have to input the words and their translation. We'll also be able to add notes about how they are used or their grammar category. Thus, we can create a list of vocabulary that we're interested in. By default, the application includes vocabulary in French, German, Italian, Portuguese, Russian and Spanish, both British and American English. The categories they cover are: clothes, education, food, health, etc.
After we have studied all this, we'll be able to complete different tests: the application will show us a word in our language and we'll have to write it in another language. We'll also be able to test reverse translation, translating the word into English. For these tests, Interlex will offer us statistics with our progress.
All in all, a simple way to learn vocabulary and be able to test your advances.