These days I have been studying English with the help of an app called Anki droid. This app is very good to learn almost any topic. It is a card software where you can put your own notes to study something and then press a button to know the answer of that note. The good thing is that you can download a very large amount of cards written by other people and study them. It has helped me a lot to increase my English vocabulary and also improve in English grammatic.