Once you have downloaded the application, all you have to do is load it with the packages of words or expressions you want to learn today, tomorrow, the day after, and so on. These packages of words and expressions will be available freely or at a very low cost to you.
The packages of words and expressions are available by categories – say, "House & Furniture", "Meeting People", "My family and I", etc. to learn what you should say, and the vocabulary you need when you meet people in a wide range of situations, and so on and so forth.
Once you have downloaded a new package of words or expressions, you can select and learn them while you are working at your computer. You can choose the ones you want to learn, and be reminded of the ones you have learned before. This way – on a daily basis - you can keep on building your new vocabulary on top of the vocabulary you have already learned.
Once you have a good range of vocabulary and expressions, you can start building your own sentences easily.