HI,
So, yes you could do that. There are some not so much caveats but different ways to do it.
1) I would create a Collection, that has Choice A, B etc in it by default. Use the Screen OnVisible to pre-populate it
add that as the Items property for the Drop down
2) have a label, + Icon and text input invisible and have the visible set to something like
MyDropDown.Selected.ColumnName Or SelectedText depending on your collection. = "Other"
you dont need to add = true or anything just the above
3) when the person types in a value in the text box, set the + Icon visible to (for adding the new option)
!IsBlank(MyOtherInput.Text And !Contains(MyOtherCollection, MyOtherInput.Text) or something like this so they cannot add the same thing 2 or more times
This will then make the + visible
4) in the + Onselect
do a Collect(MyChoicesCollection, MyOtherInput.Text)
then have it reset(MyOtherInput.Text) so that they cannot add the same thing again
5) Now it will be in the Dropdown for them to select. Or if you want to auto select it as the default, once they save it we can do that too.
But now they can add any they want, and you just have to save the Selected value into the SP List since its a text.
