A Bluetooth keyboard that connects to an iPad to serve as both a keyboard for script edits, and a wireless presenter controller to control the speed of the scroll.
The default speed of the scroll must be set on the iPad before commencing prompting, and then once prompting the keyboard space bar can be used to stop/start the scroll as necessary to control the pace as you read the script.
When in edit mode, the keyboard can be used to make changes directly to the script itself.