Portugalski - Ucz się języka is a free Android application developed by Tweeba. The app provides a comprehensive course to learn the Portuguese language, making it easy and enjoyable for beginners and advanced learners alike. The app allows learners to study Portuguese vocabulary, grammar, and pronunciation with flashcards, quizzes, and a dictionary. The course includes different topics such as basic Portuguese, colloquial language, Portuguese for school, work and business, and even for tourists and emigrants.

Furthermore, users can access two widgets to help them learn Portuguese, one for the word of the day in Portuguese and another for a Polish-Portuguese dictionary. The app offers different lessons and tests, which help learners to study progressively. The app also has an option to hide the meaning of Portuguese words in Polish to help learners memorize them. Additionally, learners can choose to randomize the words they are studying, and also listen to the correct pronunciation of Portuguese words through the app's voice-over. The app works both online and offline, and audio files are best installed using Wi-Fi.

Overall, Portugalski - Ucz się języka is an excellent option for those interested in learning Portuguese, as it provides a comprehensive course with different topics, quizzes, and tools, all for free.