"Germany is very beautiful."
I agree that we should have a bit more kanji in this course, but I think this particular sentence probably isn't the best one to have used to make this point...
- The kanji for とても isn't even required to be taught in school in Japan and isn't even found in any JLPT kanji study lists.
- The two kanji in きれい are both listed in JLPT lists as N1 (the most advanced JLPT level) and are 14 and 19 strokes each. Also, the simpler kanji you can use in place of the first of these is again still N1.
In fact, these words (ドイツ, てとも, きれい) are all listed in dictionaries as "usually written using kana alone". I think even Japanese people would probably be more likely to write this sentence without using any kanji. But here's what the sentence looks like if you go all out with kanji:
I definitely hope they do start using more kanji in this course though, especially in certain words like 日よう日... xD
You might be interested in trying out LingoDeer; it allows you to select between Romaji, kana, kanji with furigana and only kanji (except for words commonly written with kana). It also has a specific mode for practicing stroke order.
I think Duolingo is better for vocabulary practice, though, so I use both.