You can go to the app.UIFigure and change the identifiers. The image should be in the same folder as the app or the path must added to Matlab path
Alternatively, you can add a Callback function to the app itself like follows:
classdef app1 < matlab.apps.AppBase
% Properties that correspond to app components
properties (Access = public)
UIFigure matlab.ui.Figure
end
% Callbacks that handle component events
methods (Access = private)
% Code that executes after component creation
function startupFcn(app)
app.UIFigure.Name = 'Your title';
app.UIFigure.Icon = "C:\path\to\your\image\smiley.jpg";
end
end
And there you go:
