A long time ago, Memrise asked users to create a course that they wished existed, with a maximum of 50 items. I did one focusing on feminine spelling, one level of 25 words and a second level using the same words in a short phrase. I recently added audio to the phrase level.
I still think there isn’t enough emphasis on feminine spelling and pronunciation, and I think this course could be very useful. I’m considering expanding it to either 250 or 500 items if there is enough interest in it. I’ll leave the link here, and if I see people joining I’ll get to work on adding to it.