Further reading
If you have the stomach for it, the App Store review guidelines are a worthwhile read. Generally, I’ve found the App Store to be much more restrictive than the Play Store, so if you can manage to release an app on the App Store, then you are likely to succeed on the Play Store:
https://developer.apple.com/app-store/review/guidelines/
Now is a great time to start thinking more generally about your app and how you can turn it into a business. It may be that your business solely revolves around your app, or it may be that your app is just a part of a bigger business. Either way, you need to start thinking about how you will market your app to your users, so taking a look at your marketing strategy would make sense at this point. There are many books, including the excellent Cracking the Product Marketing Code: Unlocking product marketers’ potential to craft outstanding GTM strategies and win the market by Iman Bayatra.
Additionally, you will want...