public
  procedure DoShowHint(Sender: TObject);

...
procedure TForm1.DoShowHint(Sender: TObject);
begin
  StatusBar1.SimpleText := Application.Hint;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Application.OnHint := DoShowHint;
  Button1.Hint := 'Button 1|It is button 1';
  Button2.Hint := 'Button 2|It is button 2';
  Button3.Hint := 'Button 3|It is button 3';
  Form1.ShowHint := true;
end;