Anglonaut can turn any text in English into fill in the blanks exercises, which can be solved in the app. You can tailor the algorithm to adjust the number of blanks and choose the words that will always be turned into a blank. When you solve the exercise, it will be compared to the original phrase and differences will be highlighted. If you think your response is also valid but you are not sure, you can ask a teacher/native speaker to take a look.
