We built the first version of our app with RN and it turned out a mess in a while. A lot of bugs along with poor performance out of the box for a fairly large app. Many things, that native platform has, cannot be done with existing solutions for RN. For instance, large titles on iOS are not fully implemented in any of existing navigations libraries. Also there's painfully slow JSON bridge and many other small, yet annoying things. On the other hand Flutter became a really powerful and easy-to-use tool. A bit of a learning curve, of course, because of Dart, but it worth learning. Flutter offers TONS of built-in features, no JSON-bridge, AOT compilation for iOS.

While with Ionic it is possible to make mobile applications with only web technologies, Flutter is more performant and is easy to use if you are willing to learn Dart, which is a fun language. Plus, it has awesome documentation and, while its ecosystem isn't near as big as JavaScript's is, it has a good package manager called Pub and its packages are generally high quality.

I am building an app that would need at least two external APIs: a map and a payment service. I am currently building in Flutter, but I am having trouble integrating one of the external APIs with the app. I wonder (because I am still at the beginning) if I should switch to React Native or build native iOS and Android apps separately. Any advice would be appreciated!