I have the following suggestions for improvements:
1) at the dialogue section of the lessons, the current switch between Kanji / English / Romaji / Hiragana / All is not really convenient. In most of the cases, I just need to check the reading of a kanji or the English translation of a word, and it is quite cumbersome to switch the whole text, find the location where I had been, check the information I need, then switch back and find the original location again. What would definitely work better for me: implement the Kanji / English / Hiragana etc. options as on/off switches with the option to activate multiple ones at the same time. The activated readings should be displayed right under each other for every line of the dialogue. This way - for example - I could see the hiragana reading right under a kanji, and the English translation right under the hiragana reading. (An additional feature to make this even more convenient: the Kanji / English / Hiragana on/off switches could also be switched by hotkeys. This way I wouldn't even need to scroll up or move the mouse pointer to display the hiragana reading when I need help with a kanji.)
2) it would be extremely helpful to implement a mouse hover popup for instant kanji reading / translation. I.e. when the mouse pointer is kept above a kanji in the text, then a small popup window would appear with the hiragana reading and the English translation. When the pointer hovers over a hiragana / katakana word then the popup window would show the English translation and possibly the brief explanation of the grammatical structure used.
3) the same hover window could be used to add any word to the personal word bank. Currently, I can add words only from the 'Vocabulary' section, despite that sometimes I would like to add words from the grammar (or any other) section.
4) references to other lessons should be actual links taking to the referred page/section. Now, when I see e.g. "Please also review the following Grammar Points. -na kya (contracted form) ⇒ Beginner Series Season 6 Lesson 11" it is very time-consuming to look up the referred lesson and find the exact grammar point there.
5) ad banners about subscription should not be displayed when one is already a premium member.
I am a very new member, so please ignore anything above that is nonsense or what already exists somehow. Otherwise, thanks for considering my inputs!
Thank you for posting. Regarding suggestion number one: If there's a Lesson Notes PDF available for the lesson, you can see all sections under each other in it, what might help to check the content easier.
Regarding the banners, you can turn them off if you go to the My Account ---> E-mail & Banners ----> Banners.