add icon, also misc improvments

pubspec.yaml

@@ -58,6 +58,7 @@ dev_dependencies:
   # package. See that file for information about deactivating specific lint
   # rules and activating additional ones.
   flutter_lints: ^5.0.0
+  flutter_launcher_icons: ^0.13.1
 
 # For information on the generic Dart part of this file, see the
 # following page: https://dart.dev/tools/pub/pubspec
@@ -70,6 +71,11 @@ flutter:
   # the material Icons class.
   uses-material-design: true
 
+flutter_launcher_icons:
+  android: true
+  ios: true
+  image_path: "mesh-icon.png"
+
   # To add assets to your application, add an assets section, like this:
   # assets:
   #   - images/a_dot_burr.jpeg