i've added a slider and an edit field in app designer as a example,
and they will show up in the right column:
the name here is how you call them.
for example, if you want to show the current slider number in the edit field, you can add an callback function and write this in it:
function SliderValueChanged(app, event)
value = app.Slider.Value;
app.EditField.Value = value;
"Value" is a property of both slider and edit field.