If your team has a strong background in Python and you want to release some prototype soon, you could try Python and Kivy. Kivy is an open-source, cross-platform Python framework for rapid development of mobile GUIs. It supports both iOS and Android. I have passed a similar situation recently: to start a mobile app with no background in mobile development. Kivy saved me a lot of time. I could develop a prototype and release it faster than I thoght.

To be honest , You need to think these points :

• Developer Experience

• Tooling

• Maintainability

My vote for now is going with React Native with Expo , using Typescript...

With this stack You could follow some patterns and principle that the Java and python programmers are familiar with.

Typescript is a javascript Superset that you can follow Procedural , Functional and OOP approaches and an easy learning curve.

With Expo you need to concern only with the shared layer (Typescript) and the Native ones will be expo responsibility.

Please check Expo.com and try to get started using typescript.

Good performance and with EAS (paid plan) you can create a full CI CD pipeline for your app connected to the stores(Apple and Android).

If you already know how to build web apps, give Capacitor a try. You can think of it like "electron for mobile" in that you can build a web app but access native functionality. Pair it with Ionic if you want a UI kit that is optimized for mobile, or build your own UI from scratch.

A bonus to Capacitor is your app will run without modification on the web as a PWA, iOS, Android, and more.

Other tools have very slow performance. They are usually selected because someone on the team likes Angular, but your customers won't care what framework you're using. They'll just know the app is slow.

I don't know much about Xamarin but I know about PyQt and React Native.

However, I don't recommend PyQt because the apps made using PyQt are not that suitable for mobile apps. If you take a look at the PyQt interface, you will be able to see that the features are more of a desktop apps kind.

React Native uses JavaScript. React Native is immensely flexible in upgrading your apps because it allows you to formulate your app code into independent blocks.

In Xamarin, you have to write the code in .NET . The best thing about Xamarin is, that it extends the.NET developer platform with tools and libraries specifically for building apps for Android, iOS, tvOS, watchOS, macOS, and Windows

While the best choice for you depends on various factors but React Native app development is a promising overall choice. In today’s scenario, React Native has steady growth, flawless code structure, and brilliant and large community support. We suggest you go for React Native for your next project owing to its outstanding support from developers, easy availability, and cost-effectiveness.

It seems like your app is not really using any native functionality on the phone. I have experience with cross platform iOS & Android development. They are all really good tools! Xamarin (all the project on the website portfolio I attached) is awesome for accessing native functionality (NFC, Sensors, Bluetooth, etc), and I have built apps that have millions of downloads, some that hit Top 5 on Utilities, another that hit Top 50 in Finances. You just have to look at what your application intent is, it seems like it's just to read and post data. For that they are all pretty good, but you should also look into Ionic which may serve the same purpose