Check platform in flutter

I am working on migrating flutter app to flutter web. I am looking for any package supported to check platform (android, iOS or web). I have previously used package but it is not supported for flutter web. Is there any work around for this?

This constant can help

The market is flooded with mobile applications. One with the best user-interface and good performance wins the race. Similarly, the market has a lot of technologies for mobile app creations, but some of them are highly in demand. Out of them, one rising star is Flutter. Launched in 2017 by Google, Flutter became the best cross platform framework of the world. The best feature observed is Single codebase, i.e., using a single code, one can develop an app in both Android and iOS.