You should have started the app on an Android first. An Android developer license is only a one time $25 fee. Once you build it on Android, you can gauge the response and determine how much to charge on other platforms. And build it using a build once, deploy many framework, such as React Native or Flutter, that way porting it to any device would be a sinch! My piece of advice.
I remember reading years ago that people were much more likely to pay for apps (outside of games) on Apple vs Android. I wonder what the current distribution looks like.
