Rosetta Stone: Fluency Builder 12+

It would be helpful if you would have theory as well besides these excellent examples.
For example the tenses or “if clause” conditional.

Unbelievably poorly developed app, at least for iOS. For the Spanish classes there are so many exercises that simply do not work! There’s no “check answer” button or click next after you select a response, so you just have to skip endlessly and see whatever lesson you can actually complete.

There’s one grammar exercise that really made me stop using this crappy app, where you need to group some words and you simply cannot select some of them, in order to choose the category for them from the dropdown list! 17 words worked (although I had to click somewhere else on the screen, not on the actual word, but near by) and for the remaining 2 words I just couldn’t select my answer and it became so frustrating.
I couldn’t even select “check answer” with the 2 words remaining ungrouped, so I can move forward with the lesson, even if it would have considered I made 2 mistakes. I just had to skip the lesson and lose all the work and time spent up to that stupid exercise.

Everything is in german, nothing translated, the explanation is also in german. How can you design something so bad? How I am supposed to learn if everything is in german?