A free program for Android, by AllDict.

If you want to learn to speak and understand Portuguese, the best solution is to start with the dictionary. But you need more than just the dictionary: You need a way to learn the language, and that is exactly where the word trainer comes in. 

The word trainer is designed to help you to improve all aspects of your language: your pronunciation, your reading, and your writing. It also includes various exercises, which makes the app useful for any level. 

Portuguese is a very rich language with many words, which makes it a perfect language for learning. If you want to practice it, the best solution is to start with the dictionary.