Kanji and hiragana
Note: I have only been playing on my phone.
I wish that when kanji is suggested, when the only examples shown have been in hiragana (or katakana), the hiragana for the kanji could be included in the suggestion. If we can't write in kanji, and there's no way to hear it, it's pretty much a guess which one is supposed to be used.
We write Japanese sentences include kanji on mobile phone. I think you can do it as same as us. Both iphone and Android can do. We type romaji. that is spell of hiragana you like. And then we convert to kanji. We just choose correct kanji in some kanjis.
how do you type hiragana?
I've noticed that hints often suggest kanji where no such kanji are available in box-arranging exercises, if that's what you mean. This can make selecting the right word written in kana pure guesswork if one cannot remember it. It is not consistent, however—kana are shown in hints for words normally written with kanji sometimes but not others.
When I was learning Japanese in a classroom setting, we started by learning the kana alphabets first, which makes my kanji quite weak. I was very surprised to see kanji so early on on duo! If nothing else, I wish furigana would be added to the kanji so we can see the kana characters instead of guessing at which kanji looks correct.