You can achieve that by using a FlatButton that contains a Column (for showing a text below the icon) or a Row (for text next to the icon), and then having an Icon Widget and a Text widget as children.
Here's an example:
class MyPage extends StatelessWidget {
@override
Widget build(BuildContext context) =>
Scaffold(
appBar: AppBar(
title: Text("Hello world"),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
FlatButton(
onPressed: () => {},
color: Colors.orange,
padding: EdgeInsets.all(10.0),
child: Column( // Replace with a Row for horizontal icon + text
children: <Widget>[
Icon(Icons.add),
Text("Add")
],
),
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: () => {},
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
This will produce the following:
