Japanese: easy learning

I have iPhone 📱 12 and at first I was so impressed with this app that after months and months went by, I decided to purchase the app. Because it seemed like there were no problems to worry about and to upgrade one had to purchase it. How ever after purchasing the app stopped operating. The music constantly stays on very loud. The music symbol that was available with ON/OFF to cut off the music disappeared. I updated at least three X’s after purchase before writing this review hoping that one of the updates would fix the problem. I wanted to e-Mail you first but there was none provided. Please fix this problem and I will gladly give better review rating. I would like for others who are interested in upgrading your app to know you are legitimate. Thank you.