Propably lack of resources and/or demand. Making and upholding a well functioning app isn't easy or free and as far as I have understood Alexander is kinda short on money. Also if people here haven't seen it as something necessary for their progress, there wouldn't have been any reason to make it anyways.
Google play removed it for whatever reason, Im sure @Alexander has the apk, I wonder if he would make us a download link. for now the best you can do is create a shortcut, firefox is great it keeps the nofap logo