Complete at least one of the platform setup steps now, to be able to build and run your first Flutter app.
If your Mac is operating at a slow pace, then for that reason alone it is worth the upgrade to OS X 10.6 Snow Leopard. macOS supports developing Flutter apps in iOS, Android, and the web (technical preview release).
IOS EMULATOR MAC OS X MAC OS X
Mac OS X 10.6.8 Snow Leopard is an upgrade to the previous version of OS X Leopard.