Want to increase font size across entire MaterialApp? In ThemeData you have textTheme property in which you can set the TextTheme for all widgets under that MaterialApp. In TextTheme you can set TextStyle for various types of texts in you app using parameters like caption, subhead etc. You can increase the size of the font by providing value for fontSize property in TextStyle
Something like this:
If you like this question & answer and want to contribute, then write your question & answer and email to freewebmentor[@]gmail.com. Your question and answer will appear on FreeWebMentor.com and help other developers.