Framework7 vs Xamarin

I want to learn cross-platform application frameworks like React Native, Flutter, Xamarin, or Ionic, and I'm a web developer. I can learn other programming languages as well. But I'm confused about what to learn, which framework is best, and which framework will last long as the application grows further into complexity.

We are developing an AWS IoT app for large boats. The IoT devices have sensors all over the boat for engine oil pressure, position, water depth, fuel level, crew location, etc. When the boat has internet, we interact with AWS cloud using lambda and Amazon DynamoDB. When the boat is offshore, the captain and crew still need normal and emergency alerts and real-time sensor information. The crew might have an Android or IoS phone or a Windows or macOS PC to receive alerts and interact with sensors. We may use the AWS GreenGrasss edge computing solution and either MQTT or HTML for that function.

Question: We want to develop a cross-platform client to run on Windows, Mac, Android, IOS, and possibly Linux. We are primarily Python programmers, so PyQt or Kivy are options for us, but we have heard good things about React Native, Flutter, Xamarin, and others. We think an AWS Greengrass core on an RPI4 could communicate to the client with MQTT or a local webserver with a client web interface.

Any thoughts would be much appreciated.

We have experience with React Native, Flutter or Xamarin, the lion share of the native cross-platform tools used. They all allow you to create very good user experiences. You can check their reddit pages to see the beautiful designs people recreate. I highly recommend using cross platform tools vs native if your app has generic functionality that doesn't use advanced functionality of the app like VR/AR. So, for something like a dating app without those features, you would probably be better off with cross platform native instead of single platform native (swift/kotlin). If budget is low, a lot of companies have success just using Expo (a framework on top of React Native). It limits you further, but it's the easiest and most affordable to find developers with. Eventually you might decide to move away from it, but at that time ou ll have a lot more money and react native will be an easy tech to move towards.

Xamarin is the oldest of the cross platform native tools and so there's a lot more documentation and supporting libraries.

Flutter is super fast & fluid, and since it uses pixels(skia), it's even more performant than all the other technologies including native single platform. But it doesn't come with the amazing libraries that Xamarin and React Native is able to leverage