Recently I happened across the website Conjuguemos, which offers a variety of graded quizzes and drills in multiple languages: French, German, Korean, Latin, Portuguese, and Spanish. Some languages have far more learning materials than others, but I find the Portuguese ones rather handy. Since a few of the Portuguese words are still written with ü, I assume the focus is not on Brazilian Portuguese. Since my ability is quite low, I am satisfied with any version of Portuguese.
For graded activities, you must register with the site. Give it a try!