I have a step in a wizard scenario.
The user has a choice of 3 options before they can tap 'Next'.
For those 3 options do I use a select drop down list or a group of 3 radio buttons?
I would say for three options use radio buttons.
All options are clearly on the screen when the form loads and you only have one click to choose.
For more complicated lists, perhaps those that are split up by category, I would use a drop-down to avoid overwhelming the user with form elements