Better kana selection + reference
Right now you can see kana in selection menu, but I find it's a bit uncomfortable, especially when you want to compare two similar characters, for example セ and ヤ, so I think it'd better if we had like a map, where selected characters background will be a bit darker and also there were buttons on sides of a lines that will select all the characters of a line. After this you won't need to scroll down and back and will be able to see characters in a sight. This can be hard to implement and since you learn letters only once this can be useless but I think it's a great idea anyway, even though you can just search for a table in internet.
Thanks for the suggestion!
It would work for the kanas, but not for kanji and words where readings and meanings are more important. Also, as you said, you will spend much more time on kanji and vocabulary than on kanas, so this would be useful for just a short phase of the Japanese learning process. I don't think it is worth the effort.