SoloLearn - an app I think could be made fully accessible

Hello to all,
I recently found an app called SoloLearn. It allows you to learn various codes such as HTML, Python C++, etc. It even supports Swift.
I was interested, so I hit the GET button to download it.
At a first glance, accessibility is well maintained when signing up or logging into a SoloLearn account. I created my account, and that's when accessibility started to drop slightly.
There are several buttons that are labeled, and several that are not. Worst of all, some dialogs contain no back button, so you can't go back to the previous page.
However, that doesn't ruin it entirely. But I think this app actually has some hope.
I'll be contacting the developer shortly to see what can be done, and I recommend to the people viewing this to do the same.
Let's make this accessible!